4 Favorite Designs:
Zekrom (it's a huge red-eyed black metallic dragon with a generator for a tail that looks like the lovechild of Darth Vader, Megatron and a Tyrannosaurus. Need I say more?)
Tyranitar (awesome design, very menacing and brutal)
Charizard (plain ol' dragon, and one of the best-looking ones)
Samurott (Where else can you get a Pokemon that goes and carries around actual swords? Plus, samurai are always cool)
3 Least Favorite Designs:
Jynx (No. Just... no. The blackface controversy only made it worse.)
Mr. Mime (Ditto, minus the blackface.)
Girafarig (Its tail-head turns it from a "meh" giraffe Pokemon to a nightmarish freak of nature D: )
4 "meh" designs:
Reshiram (Its face, hair-tails, body shape and... "crotch fur"... look kinda weird, though I find it very cool on its other merits)
Conkeldurrhurrhurr (One of the ugliest Pokemon ever, but it's probably supposed to be that way, plus unlike Jynx and Mr. Mime it looks like it can screw you up big-time. And in competitive play, it can.)
Meganium/Emboar (My 2 least favorite fully-evolved starters in terms of design, they aren't especially awful-looking but unlike other starters they aren't especially cool either.)