They finally gave Vaporeon a really awesome sprite (especially after the crappy DP sprite) in Platinum, but then ruined it by giving us awkward tail Vaporeon. Pt's is better.
Flareon's Pt is also better, don't why they had to bend it's legs so awkwardly in HGSS...
Jolteon... No comment :I
Espeon looks more elegant, and I like it's second sprite. After downgrading the original trio Eeeveelution's sprites from Pt, it's nice to see they didn't do the same with all the others.
Umbreon<3 definitely a lot better, and I'm likin' the fierce 2nd sprite. :D
Mewtwo's sprites have always been meh. His legs have been too fat and the tail chunky and huge. And then game DPP...
Definitely awesome. And the crotch area doesn't sink down the floor anymore. But... what the hell?!
He looks like he's lacking some shading. His chest and head appear smaller. The pose is okay, but overall the coloring and awesome-ness of the DPP sprite was mostly lost. :/ At least it isn't this anymore
Oh and Delibird's 2nd sprite is adorable :3