Look at this awesomeness:
Now look at his derpness and fatness:
Why god, why?
I also dislike some of the sprite animations in the Generation V games, like most of the sprites of Gen I~IV Pokémon.
They lack creativity. And one last thing, I hate when a bird Pokémon does not open their wings in the sprites. Examples:
Edit: And most of DPPt sprites are pretty bad if compared with the HGSS ones... Really a shame.