One thing that would be cool concerning Pikachu is if they actually made evolution his taunt. For example, in the battle, you would start off as Pichu. If you press taunt, Pichu evolves into Pikachu and becomes slower but has a greater attack power. If you taunt again, Pikachu will evolve into Raichu, who will be slower but will have a greater attack power. You cannot devolve, however, but it would make Pikachu a lot more interesting.

Anyway, I can't be bothered to make a list so here are a few:

Megaman X
Zero

Banjo-Kazooie

Koopa Trooper

There you go.