Jigglypuff! I totally made a pwnage Jigglypuff on DS, lol. Then my charmander/charmeleon/charizard back in the good old day. I like a few of the legendaries, too: Mewtwo, Lugia, Mesprit (from the new game...I actually really liked its playful attitude). Can't resist the Pikachu, either.
I only know of the first batch of 150 pokemon, but from there I really like Psyduck. I dunno...I know it's modeled after a duck, but it actually reminds me more of a penguin. They're both cute in a clumsy kinda way. XD