I guess you mean what's the best,strongest,... pokémon. Well my opinion is:
Edit: Whoops,you said fastest? It's kinda hard to read a small red lettertype on a green background. Well I think it's the the speed Deoxys. Kinda obvious.
The strongest pokémon: Either Arceus or attack Deoxys. Arceus has base stats 120 for all its stats and the attack Deoxys is awfully strong.
The most popular: Probably the yellow rat. Personally I can't stand it.
The best looking: If you mean the most beautiful, then Gardevoir or Milotic. If you mean which pokémon's design I like the most, then Armaldo and Feraligatr.
The cutest: One of the baby pokémon. Cleffa, Smoochum, Igglybuff,...
The ugliest: Probopass, Magmortar, Bidoof line. They're ugly but I like Probopass and Magmortar. It doesn't matter that they're ugly.
Well I hope this is what you meant.