I believe Zapdos should be the sole S rank, its effectiveness with only one set is unmatched. You could use it in every GSC match for the rest of your life and it'd be useful in every one. You could know with absolute 100% certainty your opponent would bring one and while you can definitely try to spin that to your advantage somehow you definitely cannot punish your opponent for bringing it (over-relying on it is another thing). Spikes/EQ immune is astounding. It can even be used to switch into Raikou early in the game to feel the opponent out - when there's a Zap + Lax it's assumed Lax (or a Ground) will switch into Kou so Cloyster can be doubled into, but Zap prevents that. It can even use other sets like Light Screen (has a million uses in every situation conceivable but most notably helps against Jynx/Vap/other electrics + still shuts down Nidoking (if you don't Thief/Explode Zap with Egg or something then LK Nido is going to thud against it every time)), TWave (burning PP against Raikou can really suck and crippling other Zap is amazing), and even Whirlwind (which has more PP than Raikou's Roar for those games you're shuffling against stall teams). However, even if every non-Thunder/HPIce/ResTalk Zap suddenly disappeared into a black hole, it'd still deserve this rank.
That said, Raikou is clearly quite a bit above everything below it and should thus be S-. You don't have to look far to see its crazy consistency thanks to its perfect blend of speed, typing and bulk. Spikes/EQ weak alongside worse physical bulk (Lax) and not Sleep Talking does kinda suck if your opponent's Thunder para rate is high and he knows how to play with Spikes down, especially if Thief gets involved but Kou is still a consistent terror (and ST is also very good). Reflect can also create lots of frustrating scenarios for offensive teams, Toxic is great, it's excellent at using HP Water which Steelix and Rhydon really do not care for... I won't re-write the analysis here but in short Raikou is absolutely still in a league of its own.
As for #4, I find Cloyster to be most appropriate there. Aside from its easily evident effectiveness, I would point to the usage statistics, which we have had for team tournaments featuring GSC since early 2014 with SPL 5. With the exception of SPL 7, where it was #3 behind Zapdos, it has held the #2 spot in usage in every single other tournament since then. This is SPL 5, 6, 8 and 9, and WCoP '15, '16 and '17. Seven out of the last eight team tournaments featuring the best players have Cloyster at #2. Again, the one tournament where it didn't do this, it dropped to #3. Furthermore, if you consult the Classic playoffs replay archive
, there are five games out of 32
across 4 years where there is not at least
This is not a knock against the traditional #4, Exeggutor. While he can often struggle against tough defensive combinations of Skarmory + Tyranitar/Umbreon (+ Suicune) and it's often unable to do much to Zapdos without Exploding (not that you wouldn't take that trade), it's still a terrifying playmaker with its coverage, status, Explosion of course and even Leech Seed. You can tweak its bag of tricks to serve you however you prefer. There are some games where it just goes crazy and rips open a huge hole that makes it hard for the opponent to bounce back. Combine this with defensive utility against major threats such as M&M, Rhydon and Vaporeon and you have one excellent Pokemon. It's just that Cloyster is, well, Cloyster.
While I adore Marowak and Suicune, I think Machamp and Vaporeon should be higher to reflect the greater consistency of both them and typical offensive teams. It's easy for them to be a huge threat throughout the game; nothing takes advantage of Resting shit like they do, especially Champ. Outside of the occasional ResTalk set, he straight up beats your face in, causing sizable gaps where important parts of teams' defense used to be (not that it can't sweep). Vap tends to be craftier; it sticks around, slowly eroding teams with its extremely spammable Surf, and it can pull some nasty surprises.
I also find Nidoking to be on the more consistent side; while sometimes his power is questionable, there's almost never a game where he won't be useful and of course when he's on he's terrifying, whereas Wak and Cune have bigger downsides. Thus, I think Nido should be higher. He's a "safe" pick whereas the latter two are more risky.
So I guess to summarize, my top 14 is:
Snorlax, S Zapdos S, S- Raikou, A Cloyster Exeggutor Skarmory Steelix Gengar Tyranitar Vaporeon Machamp Nidoking Marowak Suicune, then the other A ranks (I suppose everything below this, so Forry onward, would be A-).
Heracross and Rhydon have definitely shown themselves to be low A. Speaking of, I also think Miltank is terrific but it should be the second-to-last in A thanks to Misdreavus being really powerful, and Umbreon generally finds a way onto more teams thanks to Pursuit, although Tank is a cornerstone of a very popular, strong team and like I said I think it's great, just that the others are too. The last in A should be the terrible horrible no good very bad Starmie.
I find Jynx to be far too low in B, I think over the past year it's proved it's definitely worthy of sitting at the top alongside Charizard, Dragonite and Tentacruel. Just above Blissey and Espeon. I believe Golem and Donphan should move to B as well.
Meganium and Piloswine for the top of C, they're borderline B but this would be fine for now I think.