Mamoswine, the Ice Pig.
Base stats(HP, Atk, Def, SpA, SpD, Spd)
110/130/80/60/60/80
As a huge Mamoswine fan, I had to make this discussion.
Mamoswine is a very overlooked pokemon, and it really puzzles me. Stab EQ coming from 130 base attack+ a monstrous Ice Shard? It doesn't make sense. He also has 110 Base Hp as well as 80 base defense, though his Special Defense is at a mere Base 60. He also has great ability, which is Snow Cloak, a hail equivalent of Sand Vail. Can be game breaking. The fact is that the only pokemon in the entire game that resists Mamo's moves is Bronzong, which can be countered. Now what really catches people's eye when they see him is his Ice Shard. A Life Orbed Ice Shard with a + attack nature will do Base stats(HP, Atk, Def, SpA, SpD, Spd)
110/130/80/60/60/80
As a huge Mamoswine fan, I had to make this discussion.

112.29% - 132.12% on a 6 Hp/0 Defense Garchomp and 95.71% - 112.62% on a 252 hp/ 0 defense garchomp, which you will most likely never face. This makes Mamoswine easily the best Scarfchomp counter in the game. Especially considering the popularity of Garchomp, which is almost always Scarfchomp nowadays.
All of the below calculations assume that Mamoswine has 252 attack evs and a + attack nature.
Life Orbed Ice Shard on Salamence After an Intimidate does 93.98% - 110.54% if it has 6 Hp/ 0 defense evs, which is an almost guaranteed kill. In the case that it has 112 Hp/ 0 Defense evs for the Dragon Dancer set, an Intimidated Ice Shard will do Damage: 86.91% - 102.23% will won't generally OHKO ,but will cripple Salamence. This will always OHKO if Stealth Rock is active. Without Intimidate, Ice Shard will OHKO even a bulky Salamence variant.
Choice Banded Ice Shard will always OHKO Salamence and Garchomp, and if Intimidated, Ice Shard will do 106.93% - 125.60% on 6 Hp/ 0 defense salamence. It will also do Damage: 98.89% - 116.16% to 112 Hp/ 0 defense Salamence, an almost guaranteed OHKO.
Another pokemon that Mamoswine can rape with Ice Shard is Gliscor. A Life Orbed Ice Shard will do Damage: 68.36% - 80.51%, while with Choice Band it will do Damage: 77.68% - 91.24%, an essentially guaranteed OHKO with Stealth Rocks in play. However, there is a 0.32% chance it will survive. Being known that Gliscor, Garchomp, and Tyranitar get owned by Mamoswine, Mamoswine is a perfect solution to combating sandstream teams.
Mamoswine also posesses an Earthquake that topples buildings. Some important calculations for this are:
Life Orb Earthquake vs. Forretress- 252 Hp / 96 Defense
42.66% - 50.00% Can 2OHKO with the help of Stealth Rock.
Choice Band Earthquake vs. Forretress- 252 Hp / 96 Defense
48.87% - 57.34%- Wow.
Life Orb Earthquake vs. Forretress- 252 Hp / 252 Defense
38.14% - 44.92% 2OHKOS with stealth rock in play, however has a slim chance of surviving with leftovers if there is a very low damage roll.
Choice Band Earthquake vs. Forretress- 252 Hp / 252 Defense
43.79% - 51.41% Guaranteed 2OHKO with Stealth Rock in play.
Earthquake also OHKOS Metagross and Tyranitar if holding Life Orb/ Choice Band.
Mamoswine's third essential move is Stone Edge. The only thing that this will actually be important for is:
Life Orb Stone Edge vs. Gyarados- 212 hp- 180 defense- No Intimidate.
Damage: 78.68% - 92.64%- This will OHKO with Stealth Rock in play, however the accuracy might let you down.
With Intimidate active, the damage will be 52.79% - 62.18%.
Choice Band Stone Edge vs Gyarados- 212 hp- 180 defense- No Intimidate- 92.97% - 109.11%- Has a decent chance at an OHKO, but will always get job done with Stealth Rock. With Intimidate active, it will do 62.24% - 73.18%.
4th Slot: Choose from list below.
Physical Moves:
Peck- OHKOS Heracross with a Choice Band equipped.
Rock Slide- Better pp and accuracy that Stone Edge, but much less powerful.
Ice Fang- Another filler, will OHKO Gliscor regardless of Life Orb or Choice Band.
Avalanche- Will have 180 BP factoring in stab, but makes you go second which can be fatal to Mamoswine.
Double Edge- Respecatble damage, yet not very good with Life Orb recoil, can be easily put on CB sets.
Special Moves:(Don't laugh, read first)
Blizzard- Before you laugh, think about what this can do in a hail team. No one will expect a mixed Mamoswine, and this will seriously dent Hippowdon as well as OHKO Gliscor. Also hits Weezing. If you are crazy enough to try this, always use Life Orb with it.
Ice Beam- Basically the option outside of Hail. Not advised at all.
Support Moves:
Light Screen- Can work well in Curse set, with both defenses high it can decently take hits.
Curse- Works great with Ice Shard, and can cause this guy to hit very hard. Not very popular due to lack of a recovery move.
Toxic- The sole purpose is crippling Cresselia, and that is it.
Substitute- A true filler, but can work well with the priority of Ice Shard.
Stealth Rock- Game breaking move, but harder to set up due to weaknesses and average defenses.
Overall, Mamoswine has a limited movepool, but it can work well with it. Has two great STABS, being Ice and Ground, and being only resisted by Bronzong. Considered this generation's "Dragon Slayer."