Note to QC: This isn't so much an update as a complete overhaul. All of the relevant new UU threats have been accounted for, and the priority listings for its sets have been changed with good reason. Enjoy the read.
http://www.serebii.net/pokedex-bw/034.shtml
[Overview]
<p>Nidoking has always been a fierce competitor in the lower tiers, and it only seems to improve with each new generation. Black and White has been especially kind to the UU veteran, bestowing upon it Sheer Force, one of the best offensive abilities in the game. In conjunction with its peerless coverage, immunity to Thunder Wave and Toxic Spikes, and key resistances to Rock-, Electric-, and Fighting-type moves, Nidoking is also one of the easiest Pokemon to toss onto a team. Its Achilles' heel, however, would definitely have to be its stats; its less-than-ideal Speed and mediocre defenses are, thankfully, punishing enough to keep this monster at bay.</p>
[SET]
name: Special Attacker
move 1: Earth Power
move 2: Sludge Wave
move 3: Ice Beam
move 4: Focus Blast / Thunderbolt / Fire Blast
item: Life Orb
ability: Sheer Force
nature: Timid
evs: 4 HP / 252 SpA / 252 Spe
[SET COMMENTS]
<p>This is the only set Nidoking needs to bring the pain in UU. Between its unique, nearly unresisted dual STAB combination, plethora of coverage moves, and the power of both Sheer Force and Life Orb backing its modest Special Attack stat, most Pokemon will have a tough time switching into it safely. Earth Power and Sludge Wave are Nidoking's main attacking options, sporting both brilliant offensive coverage and synergy; Earth Power lays waste to any grounded Rock-, Steel-, or Fire-type Pokemon that dare to take it on—including the likes of Empoleon, Registeel, Arcanine, and Rhyperior. Sludge Wave covers the Grass-types that resist Earth Power, such as Shaymin, and deals heavy damage to Flying-types or other targets neutral to Poison, such as Zapdos and Honckrow. Any Steel-types brave enough to switch into Sludge Wave are brutally massacred by Earth Power, save for Bronzong, who is handily dispatched by Nidoking's coverage moves. Ice Beam KOs Ground- and Flying-types attempting to check Nidoking, such as Gligar, Hippopotas, Flygon, Zapdos, and Crobat. Coverage on Crobat and Flygon is especially important, as both resist its dual STAB combination and the latter is extremely common in UU.</p>
<p>The final slot is where things get tricky. While Poison / Ground / Ice coverage is nigh-perfect in UU, there are some targets Nidoking fails to 2HKO simply because it isn't strong enough. Premier special tanks Umbreon and Snorlax wall it consummately unless it runs Focus Blast, whereas specially bulky Water-types such as Suicune, Milotic, and Slowking can cause trouble if it isn't packing Thunderbolt. Lastly, but not least, Fire Blast is used mainly to KO Bronzong, whose presence in UU is too great to ignore.</p>
[ADDITIONAL COMMENTS]
<p>Taunt is an interesting move for Nidoking, as it denies slower targets that cannot damage it significantly, such as Umbreon, of both recovery and setup opportunities. Substitute allows Nidoking to foil some of its faster checks, but it's usually better off damaging its switch-ins through attacking. Shadow Ball is probably the most useful of Nidoking's less explored attacking options, as it lets Nidkoing threaten its Psychic-type enemies on the switch, but it may leave Nidoking vulnerable to other important targets.</p>
<p>Since Nidoking often has trouble with faster offensive Pokemon and special tanks, an ally that can take many hits as well as dish them out is preferred. Nothing epitomizes bulky offense in UU quite like Snorlax; it handily counters Porygon-2 and Rotom-H, and can deal heavy damage to its switch-ins with a Choice Band STAB Return. Most Psychic-types attempting to check Nidoking are also checked by Snorlax, who can eliminate them with its powerful Crunch or Pursuit. Cobalion is another fine partner for Nidoking, crushing both Umbreon and Snorlax with its STAB Fighting attacks, as well as luring in any Choice Scarf Heracross for Nidoking to handily switch in on. Much like Cobalion, Escavalier has a great set of resistances, as well as a reputation for manhandling specially defensive Pokemon. However, its most outstanding quality as a partner to Nidoking is its ability to destroy Psychic-types with its absurd base 135 Attack and STAB Megahorn. It must be wary of Mew, however, who can put it out of commission with Flamethrower, or burn it with Will-O-Wisp as it switches in.</p>
[SET]
name: Choice Scarf
move 1: Earth Power
move 2: Sludge Wave / Fire Blast
move 3: Ice Beam
move 4: Shadow Ball
item: Choice Scarf
ability: Sheer Force
nature: Modest / Timid
evs: 4 HP / 252 SpA / 252 Spe
[SET COMMENTS]
<p>While it may seem like a waste for a Pokemon with Nidoking's impeccable coverage to lock itself into one move, Nidoking has just the right moves to punish offensive Pokemon attempting a sweep, and a Sheer Force boost to make the endeavor worthwhile. With a Choice Scarf attached, Nidoking is now capable of taking on faster Pokemon it wouldn't normally dream of beating one-on-one, such as Victini and Azelf. Earth Power is its mandatory STAB attack to threaten not only its usual targets, but even the likes of Raikou and Cobalion, which it can now check without fear of taking a boosted attack. Ice Beam allows Nidoking to check faster Flying- and Ground-types, such as Togekiss, Flygon, and Zapdos.<p>
<p>One of the most striking differences between this set and the standard special attacking set is the addition of Shadow Ball to Nidoking's arsenal, which allows it to revenge KO prominent Psychic- and Ghost-type sweepers such as Mew, Azelf, and Mismagius. Fire Blast is also viable as it offers similar coverage to Sludge Wave, and greater greater super effective coverage in exchange for the STAB boost. Still, for a powerful, all-purpose attack, you won't get much better than Sludge Wave.</p>
[ADDITIONAL COMMENTS]
<p>Modest is the preferred nature on this set for some much-needed power behind Nidoking's attacks, and Nidoking retains just enough Speed to outpace anything in UU that isn't itself equipped with a Choice Scarf. Timid is also usable, however, for tying with or outspeeding some of the more common Pokemon equipped with Choice Scarves, such as Chandelure, Heracross, and Adamant Krookodile. In addition, Timid Nidoking also outspeeds Adamant Kingdra after a Dragon Dance.</p>
<p>Without a Life Orb, Nidoking is significantly less powerful, and more checks, such as Suicune and Milotic, begin to crop up. Heracross is a fantastic answer to these Pokemon, taking their Scalds with ease, and abusing Scald's burn effect to power up Guts for even more destruction. If one can afford the moveslot, Thunderbolt is a viable alternative for keeping bulky Water-types in check, 2HKOing all but the most specially defensive of targets after Stealth Rock damage.</p>
<p>Defensive pivots such as Bronzong, Gligar, and physically defensive Zapdos are also desirable partners for Nidoking, as dangerous offensive Ground-types such as Flygon, Krookodile, and Rhyperior can all very easily take advantage of a Nidoking locked into Sludge Wave. As a bonus, Gligar can deftly wall all three of the aforementioned threats, in addition to Stoutland, Choice Scarf Darmanitan, and Choice Scarf Victini.</p>
[Other Options]
<p>With an impressive repertoire of physical attacks such as STAB Earthquake, Megahorn, Head Smash, Superpower, and the elemental punches, Nidoking has the often overlooked potential to go physical. Unfortunately, most of these moves moves are incompatible with Sheer Force, making a physical set much less viable overall. Sucker Punch is useful for taking out faster checks that have been weakened considerably, and is most effective when attempting a mixed sweeping set with Hone Claws. The accuracy boost from Hone Claws also allows it to use Blizzard and Thunder with nigh-perfect accuracy, making it a gimmicky, but considerably more attractive option.</p>
[Checks and Counters]
<p>Bulky Psychic-types are by and large Nidoking's greatest obstacles. Defensive variants of Mew, Cresselia, and Deoxys-D can all avoid the 2HKO from Sludge Wave, recover health, and begin to set up, or force Nidoking out immediately with the threat of a lethal Psychic-type attack. Uxie is also a great check to Nidoking thanks to Levitate and great defenses, allowing it many opportunities to switch in and set up screens or Calm Mind. Specially defensive tanks do not fear Nidoking unless it is packing the right coverage moves to beat them. This makes Porygon2, Clefable, Snorlax, and Umbreon all excellent switch-ins if it is not carrying Focus Blast.</p>
<p>Base 85 Speed isn't very impressive in UU, and Nidoking happens to miss the mark on some of the most dangerous offensive Pokemon in the tier. Rotom-H, Roserade, Darmanitan, Shaymin, and many others can force it out with the threat of a swift OHKO. Rotom-H in particular plagues most Nidoking, thanks to its immunity to Earth Power and handy resistances to Ice Beam, Thunderbolt, and Fire Blast. Froslass is another dangerous Pokemon for Nidoking to face, as it can switch in on Sludge Wave and threaten to KO with Ice Beam, or set up Spikes as Nidoking switches.</p>

http://www.serebii.net/pokedex-bw/034.shtml
[Overview]
<p>Nidoking has always been a fierce competitor in the lower tiers, and it only seems to improve with each new generation. Black and White has been especially kind to the UU veteran, bestowing upon it Sheer Force, one of the best offensive abilities in the game. In conjunction with its peerless coverage, immunity to Thunder Wave and Toxic Spikes, and key resistances to Rock-, Electric-, and Fighting-type moves, Nidoking is also one of the easiest Pokemon to toss onto a team. Its Achilles' heel, however, would definitely have to be its stats; its less-than-ideal Speed and mediocre defenses are, thankfully, punishing enough to keep this monster at bay.</p>
[SET]
name: Special Attacker
move 1: Earth Power
move 2: Sludge Wave
move 3: Ice Beam
move 4: Focus Blast / Thunderbolt / Fire Blast
item: Life Orb
ability: Sheer Force
nature: Timid
evs: 4 HP / 252 SpA / 252 Spe
[SET COMMENTS]
<p>This is the only set Nidoking needs to bring the pain in UU. Between its unique, nearly unresisted dual STAB combination, plethora of coverage moves, and the power of both Sheer Force and Life Orb backing its modest Special Attack stat, most Pokemon will have a tough time switching into it safely. Earth Power and Sludge Wave are Nidoking's main attacking options, sporting both brilliant offensive coverage and synergy; Earth Power lays waste to any grounded Rock-, Steel-, or Fire-type Pokemon that dare to take it on—including the likes of Empoleon, Registeel, Arcanine, and Rhyperior. Sludge Wave covers the Grass-types that resist Earth Power, such as Shaymin, and deals heavy damage to Flying-types or other targets neutral to Poison, such as Zapdos and Honckrow. Any Steel-types brave enough to switch into Sludge Wave are brutally massacred by Earth Power, save for Bronzong, who is handily dispatched by Nidoking's coverage moves. Ice Beam KOs Ground- and Flying-types attempting to check Nidoking, such as Gligar, Hippopotas, Flygon, Zapdos, and Crobat. Coverage on Crobat and Flygon is especially important, as both resist its dual STAB combination and the latter is extremely common in UU.</p>
<p>The final slot is where things get tricky. While Poison / Ground / Ice coverage is nigh-perfect in UU, there are some targets Nidoking fails to 2HKO simply because it isn't strong enough. Premier special tanks Umbreon and Snorlax wall it consummately unless it runs Focus Blast, whereas specially bulky Water-types such as Suicune, Milotic, and Slowking can cause trouble if it isn't packing Thunderbolt. Lastly, but not least, Fire Blast is used mainly to KO Bronzong, whose presence in UU is too great to ignore.</p>
[ADDITIONAL COMMENTS]
<p>Taunt is an interesting move for Nidoking, as it denies slower targets that cannot damage it significantly, such as Umbreon, of both recovery and setup opportunities. Substitute allows Nidoking to foil some of its faster checks, but it's usually better off damaging its switch-ins through attacking. Shadow Ball is probably the most useful of Nidoking's less explored attacking options, as it lets Nidkoing threaten its Psychic-type enemies on the switch, but it may leave Nidoking vulnerable to other important targets.</p>
<p>Since Nidoking often has trouble with faster offensive Pokemon and special tanks, an ally that can take many hits as well as dish them out is preferred. Nothing epitomizes bulky offense in UU quite like Snorlax; it handily counters Porygon-2 and Rotom-H, and can deal heavy damage to its switch-ins with a Choice Band STAB Return. Most Psychic-types attempting to check Nidoking are also checked by Snorlax, who can eliminate them with its powerful Crunch or Pursuit. Cobalion is another fine partner for Nidoking, crushing both Umbreon and Snorlax with its STAB Fighting attacks, as well as luring in any Choice Scarf Heracross for Nidoking to handily switch in on. Much like Cobalion, Escavalier has a great set of resistances, as well as a reputation for manhandling specially defensive Pokemon. However, its most outstanding quality as a partner to Nidoking is its ability to destroy Psychic-types with its absurd base 135 Attack and STAB Megahorn. It must be wary of Mew, however, who can put it out of commission with Flamethrower, or burn it with Will-O-Wisp as it switches in.</p>
[SET]
name: Choice Scarf
move 1: Earth Power
move 2: Sludge Wave / Fire Blast
move 3: Ice Beam
move 4: Shadow Ball
item: Choice Scarf
ability: Sheer Force
nature: Modest / Timid
evs: 4 HP / 252 SpA / 252 Spe
[SET COMMENTS]
<p>While it may seem like a waste for a Pokemon with Nidoking's impeccable coverage to lock itself into one move, Nidoking has just the right moves to punish offensive Pokemon attempting a sweep, and a Sheer Force boost to make the endeavor worthwhile. With a Choice Scarf attached, Nidoking is now capable of taking on faster Pokemon it wouldn't normally dream of beating one-on-one, such as Victini and Azelf. Earth Power is its mandatory STAB attack to threaten not only its usual targets, but even the likes of Raikou and Cobalion, which it can now check without fear of taking a boosted attack. Ice Beam allows Nidoking to check faster Flying- and Ground-types, such as Togekiss, Flygon, and Zapdos.<p>
<p>One of the most striking differences between this set and the standard special attacking set is the addition of Shadow Ball to Nidoking's arsenal, which allows it to revenge KO prominent Psychic- and Ghost-type sweepers such as Mew, Azelf, and Mismagius. Fire Blast is also viable as it offers similar coverage to Sludge Wave, and greater greater super effective coverage in exchange for the STAB boost. Still, for a powerful, all-purpose attack, you won't get much better than Sludge Wave.</p>
[ADDITIONAL COMMENTS]
<p>Modest is the preferred nature on this set for some much-needed power behind Nidoking's attacks, and Nidoking retains just enough Speed to outpace anything in UU that isn't itself equipped with a Choice Scarf. Timid is also usable, however, for tying with or outspeeding some of the more common Pokemon equipped with Choice Scarves, such as Chandelure, Heracross, and Adamant Krookodile. In addition, Timid Nidoking also outspeeds Adamant Kingdra after a Dragon Dance.</p>
<p>Without a Life Orb, Nidoking is significantly less powerful, and more checks, such as Suicune and Milotic, begin to crop up. Heracross is a fantastic answer to these Pokemon, taking their Scalds with ease, and abusing Scald's burn effect to power up Guts for even more destruction. If one can afford the moveslot, Thunderbolt is a viable alternative for keeping bulky Water-types in check, 2HKOing all but the most specially defensive of targets after Stealth Rock damage.</p>
<p>Defensive pivots such as Bronzong, Gligar, and physically defensive Zapdos are also desirable partners for Nidoking, as dangerous offensive Ground-types such as Flygon, Krookodile, and Rhyperior can all very easily take advantage of a Nidoking locked into Sludge Wave. As a bonus, Gligar can deftly wall all three of the aforementioned threats, in addition to Stoutland, Choice Scarf Darmanitan, and Choice Scarf Victini.</p>
[Other Options]
<p>With an impressive repertoire of physical attacks such as STAB Earthquake, Megahorn, Head Smash, Superpower, and the elemental punches, Nidoking has the often overlooked potential to go physical. Unfortunately, most of these moves moves are incompatible with Sheer Force, making a physical set much less viable overall. Sucker Punch is useful for taking out faster checks that have been weakened considerably, and is most effective when attempting a mixed sweeping set with Hone Claws. The accuracy boost from Hone Claws also allows it to use Blizzard and Thunder with nigh-perfect accuracy, making it a gimmicky, but considerably more attractive option.</p>
[Checks and Counters]
<p>Bulky Psychic-types are by and large Nidoking's greatest obstacles. Defensive variants of Mew, Cresselia, and Deoxys-D can all avoid the 2HKO from Sludge Wave, recover health, and begin to set up, or force Nidoking out immediately with the threat of a lethal Psychic-type attack. Uxie is also a great check to Nidoking thanks to Levitate and great defenses, allowing it many opportunities to switch in and set up screens or Calm Mind. Specially defensive tanks do not fear Nidoking unless it is packing the right coverage moves to beat them. This makes Porygon2, Clefable, Snorlax, and Umbreon all excellent switch-ins if it is not carrying Focus Blast.</p>
<p>Base 85 Speed isn't very impressive in UU, and Nidoking happens to miss the mark on some of the most dangerous offensive Pokemon in the tier. Rotom-H, Roserade, Darmanitan, Shaymin, and many others can force it out with the threat of a swift OHKO. Rotom-H in particular plagues most Nidoking, thanks to its immunity to Earth Power and handy resistances to Ice Beam, Thunderbolt, and Fire Blast. Froslass is another dangerous Pokemon for Nidoking to face, as it can switch in on Sludge Wave and threaten to KO with Ice Beam, or set up Spikes as Nidoking switches.</p>