Pokemon you would actually redesign

[skyradiant]

I'd redesign Aerodactyl, so that it looks more like an actual pterosaur rather than a dragon.

 

[Champion Red]

Ooh, here's some more:

Dragonite. Make it blue, and more serpentine, more like a Dragonair/Gyarados hybrid, preferably a Dragon/Water type. Make it look more intimidating and dragon-like as well, with cooler wings

Aerodactyl. Make it look more like a pterosaur, and make its mega look cooler then just a bunch of rocks on it

Raichu. Retain the cuteness of Pikachu a bit more please

Tyranitar. Make it look more dinosaur-like, tone down all the spikes and stuff

 

[Misty-Moo]

Something that's bugged me since the Kalos starters were introduced is their secondary typing -
Grass/Fighting, Fire/Psychic & Water/Dark
It would have been so much more interesting if they'd been -
Grass/Dark, Fire/Psychic & Water/Fighting (Greninja's even got a Fighting-esque name)