It is lame in the later gens, but I disagree it began with Yellow. Red and Blue have some great sprites. There's a lot of stinkers (Ekans, Cloyster, Tangela, Venomoth), but there's a lot that are really dynamic or full of personality (Goldeen, Poliwrath, Haunter, Gloom, Golbat Ivysaur,). And then, there's some that I just love because they're so adorable (Pikachu, Sandshrew, Pidgeotto, Nidoran-F, Nidorina, Dratini, Butterfree).
Special mention to Ditto for looking better than it has in maybe any other sprite - actually having weight, and coming off as a kind of weird, possibly even metallic gloop.
