I’m going to start a Viability Rankings on here. Post anything if you want to nominate anything to drop or rise
GSC PU VR 
S Rank
(These Pokemon define the metagame, and fit on all sorts of teams with little flaws)
01:
(Furret is the face of PU. It’s speed is excellent, it’s Double Edge hits incredibly hard, and its quite diverse with its great coverage. It fits on almost every single time, and can easily turn the tide of games with how strong it is )
02:
(Venomoth has immense defensive and offensive utility in countering Hitmonchan and is incredibly splashable and versatile. It’s one of the best leads in the metagame as well )
03:
(Seadra is one of the hardest hitters in the tier, being nigh impossible to wall without a Drowzee. It also can shut down Baton Pass with Haze)
04:
(May be controversial, but Murkrow is clearly S Rank imo. Having Haze and being faster then Poliwhirl and the various other base 90s while being a dangerous mixed attacker in its own right with Pursuit make it one of the top Pokemon)
05:
(Kid is an excellent offensive threat in its own right, but it also is an important Pokemon since it has the role of revenge killing Poliwhirl and Thief)
A Rank
(These Pokemon are not as splashable as the S Ranks and have more flaws, but they remain important metagame threats)
A+ Rank
06:
(Hitmonchan is incredibly splashable. Having a Rapid Spinner that can hit very hard while checking Seadra and Elekid is a huge niche)
07:
(Drowzee is one of the best defensive Pokemon, being among the few Pokemon to check Seadra while also dominating Venomoth, Hitmonchan, Hitmontop, and Elekid
08:
(Tangela is another amazing defensive Pokemon. While it’s low SpDef can really bite at teams, it’s probably the best physical wall in the tier, and can setup reliably with Growth or Swords Dance)
09:
(Abra is an incredibly powerful offensive threat, with Psychic barely scarcely resisted and it having many good supporting moves such as Encore or Thunder Wave. Shoutouts for
File 13 for the Twisted Spoon calcs)
10:
(The meta has adapted to Poliwhirl. Murkrow and Elekid are everywhere, and virtually every team has a base 90 speed mon, meaning it has to rely on speed ties to sweep. I find it’s only really valuable in the lategame
11:
(Aipom is the face of one of the most viable play styles in the tier, Baton Pass. It’s also surprisingly bulky, which lets it reliably pass Agility)
A Rank
12:
(Golbat is very annoying to play against with the combination of Toxic, Protect, and Haze. It’s a mainstay on defensive teams as a result, although it can let Abra in for free)
13:
(Omanyte is the hardest Furret counter in the tier. It also has solid offensive capabilities and Thief for walls such as Drowzee)
14:
(Seaking can be a hugely dangerous threat at times. SD Return RestTalk sets have been seeing usage lately and they seem to be doing well)
15:
(Top tends to prefer to sweep with Curse. It has serious issues with how common Venomoth and Abra are though. It can definitely snowball and potentially sweep with the right support though)
16:
(The absolute hardest counter to Venomoth, while also checking Murkrow really well. It has a ton of common weaknesses, however, and lets in Seadra for free)
17:
(Cubone is the best speed recipient in the tier. If it manages to get +2 Attack and +2 Speed, the game is likely over. The prominence of Haze Seadra hurts it though)
18
(Mantine is an incredible special wall with Haze. It has rather poor physical bulk, however, and a nasty 4x weakness to Electric)
19:
Noctowl takes a good few Curse boosts to start doing serious damage, and faces competition from Furret. It’s huge special bulk and access to moves such as Nightmare and Hypnosis give it a niche though
20:
(Voltorb is the best lead in the current metagame with its variety of support moves and its unmatched speed. It also checks the newly popular Miracle Berry Murkrow leads nicely)
21:
(Clef is a threatening sweeper with Curse, Moonlight, and Thunder Wave. It struggles with how prominent Haze is as a move, and is very weak until it gets quite a few Curse boosts)
22:
(Rhyhorn is the best Rock-type in tier with its solid offensive and defensive potential. It’s a great counter to mono Curse RestTalk Furret with Roar, and can Roar out Baton Pass users)
23:
(Machoke has solid physical bulk, and Light Screen, a hugely useful move for its teamates. It’s much better against Poison and Flying types as well, with crucial coverage in Rock Slide and Earthquake)
24:
(Flaaffy is the best counter to Elekid available in the tier, and is a fierce offensive threat with how few Pokemon resit’s Electric)
A- Rank
25:
(Charmeleon is a dangerous Sunny Day attacker with Fire Blast, Sunny Day, Rest, and Sleep Talk. It can easily break through defensive teams lacking a Fire resist
26:
(It may seem odd that the premier Spiker of the tier is this low, but Delibird is not a consistent Spiker at all with its frailty. Rapid Spin is also very common, meaning it’s unlikely for it’s Spikes to actually stay throughout the game
27:
(Gastly struggles a ton with the prominence of Murkrow. It’s generally inconsistent with its poor speed and horrible bulk. It doesnt scare Furret, the Pokemon it’s meant to check, as well)
28:
(As the only legal Heal Bell user in the tier, Snubbull has a place on some defensive teams)
29:
(Staryu is a niche Rapid Spin user with Recover. It also has Thunder Wave and good coverage to scare off some threats such as Rhyhorn)
30:
(Magby is a fierce threat under sun, and has Thunder Punch to annoy Seadra and Mantine. It’s very difficult to switch in though)
31:
(Sunflora is somewhat like a specially defensive version of Tangela. However, it lacks Stun Spore and Sleep Powder, meaning it has to rely on Toxic to do any damage to Fire-types
32:
(Ariados faces a bit of competition from Aipom as an Agility Passer. It does have a niche as the only Pokemon to be able to pass a trapping move though
33:
(Ponyta is really fast, and has Hypnosis. It’s quite good on some offensive teams since it scare Pokemon such as Tangela out)
34:
(Bayleef is an great mixed wall with Reflect, Stun Spore, and Light Screen.Its very passive though, and venerable to status
B Rank
(
These Pokemon are generally hard to fit and have quite a number of flaws that keep them from seeing more usage)
35:
(Tentacool is a Toxic immune Rapid Spinner. It Is incredibly passive though)
36:
(Grimer is a decent Curse sweeper with Explosion and decent special defense)
37:
(Slowpoke is really pressured by Murkrow and has very poor Special Defense. It does completely counter Curse Hitmontop, however.
38:
(Geodude is a niche Rapid Spin user with Explosion and STAB Earthquake for Gastly)
39:
(Eevee is the only Pokemon capable of Baton Passing Growth, a potentially lethal scenario is it passing to a Seadra or Abra)
40:
(Wobb requires Spikes and Toxic support, but it can be incredibly tough to take down, as it is the absolute bulkiest Pokemon in the tier)
41:
(Parasect faces a lot of common from Tangela, although Parasect is much better off against Seadra due to its better SpDef)
42:
(Faces competition from Omanyte, but Corsola does have Recover and a niche on Sand teams, which seem to be decent)
43:
(Beedrill is a good Double Dancer with Swords Dance and Agility, that can clean up some games. It’s generally quite inconsistent though)
44:
(Doduo is extremely frail, but it can be a dangerous late game cleaner with a unique Endure, Flail, Agility set)
45:
(A niche Grass-type with Encore and Stun Spore)
46:
(Wartortle faces a lot of competition from Tentacool, although it doesn’t have better Defense for switching into Rhyhorn)
C Rank
(
These Pokemon are very rarely worth using and have difficult flaws to overcome)
47:
(Weep is a usable Grass-type sweeper if passed speed)
48:
(Roar is nice, but Haze is much more valuable then Roar and Whirlwind due to the lack of Spikes. Croc is also outclassed by other defensive Waters such as Mantine)
49:
(Nidorina is a weak Poison-type that has poor bulk and a weakness to Psychic. It might be able to do something with Thief and Moonlight)
50:
(Despite being fast, Diglett is very weak and OHKOd by almost everything)
51:
(Dratini resists Water and Fire and has Thunder Wave and dual screens. It’s very weak and frail though)
52:
(Shellder has almost no Special Defense, but it has Explosion and usable physical bulk)
53:
(Natu is not like his big brother in NU, it’s almost entirely outclassed by Abra. At least it can Drill Peck and Haze)
54:
(To the guy running SunnyBeam Togetic on ladder, please show me your ways)
D Rank
(These Pokemon are just bad all around, and are virtually never worth using)
55:
(A semi good check to a Elekid with Belly Drum, but it’s very weak even at +6, is frail, and is incredibly slow)
56:
(Krabby has no SpDef, is slow, and very inconsistent)
57:
(Niche Ancient Power Sweeper that’s inconsistent and frail)
58:
(Baton Pass user with Light Screen and Barrier. Aipom and Ariados are better though)
59:
(Use Geodude instead. At least it has Swords Dance)
60:
(Frail Fighting-type with Meditate with a super awkward speed tier)
61:
(lol)
Other Pokemon that might be viable / Untested Rank
Growlithe
Phanpy
Smoochum
Rattata
Teddiursa
Psyduck
Swinub
Larvitar
Ditto
Ivysaur
Quilava
Onix
