Good Lord, this thread is almost just full of nothing.
First off, allow me to say this. No, no, and NO!!! to Mew, Deoxys-LG, etc. Deoxys-S (or E for some of you) is good enough. Second place to perhaps be considered: between Dewless
Lati@s, and if we want to go EXTREMELY far into this discussion maybe Wobbuffet... Considering anything else is just stupid. Ho-oh was discussed already and was said no, so don't bring that up either.
Mew for one can Baton Pass ANYTHING ALMOST! Calm Mind, Nasty Plot, Swords Dance, are you getting it yet? It's movepool is basically insane (remember Transform too, as he makes a better Ditto even). His 100 stats barely even come into the playbook, because to me that movepool alone keeps it up there. Is Mew counterable? No. Reason? Unpredictable movepool, it's just that simple. He's cool and all but... let's keep him where he belongs: Uber.
Manaphy with RainRest and Tail Glow also is just nuts. Name one, I dare, ONE POKEMON that can actually switch into Manaphy from OU. Thinking hard yet? The closest, perhaps, would be Blissey. Maybe Vaporeon if he carries Surf and Ice Beam, etc. He's just that hard to counter. Forget using Toxic to cripple him, as RainRest cancels it out.
We've discussed Darkrai. He's basically a better Gengar without the resists (minus Pursuit). I saw it mentioned here, alright?
Deoxys-LG can't be compared as a better Cresselia... per se. You see, his main disadvantage is his HP. However, he does have Recover, can lay Spikes OR Stealth Rock, and just do alot of other things. I don't think he should be considered at all.
Wobbuffet. Alright, I think personally the whole "Pokemon X counters Wobbuffet" is stupid alright. Some of you boneheads forgot one thing: Shadow Tag and Encore. If he Encore's your Swords Dance, what the hell can you do? Just sit there I guess until he switches to a counter. What about your pitiful attempt to switch out? Oh wait... you're trapped! Ah well, guess you can't do much except sit there and die when he grabs a counter against you. You could attack, but may though things could 2HKO Wobbuffet, guess what Counter and Mirror Coat could do back at you?... OHKO in other words. Once he switches out, you're still trapped THAT turn. He basically has a free switch into perhaps a BellyZard and you just lost since you're locked onto Swords Dance and BellyZard is free to set up his Substitute while you switch out, and then Belly Drum after the Substitute is broken, and finally sweep your ass into oblivion. Now what? Don't say the whole "you gotta sacrifice Pokemon Y to get Wobbuffet out" either. I could just wait until your Suicune attempts a Calm Mind and then switch Wobbuffet in. It's not that hard of a concept. Could you at least make a semi-intellignet post before rambling about "you can't switch into CB Chomp" because I wouldn't be stupid enough to do it in the first place.
DUH.