There are a ton of Anime / Manga based game... To many to count. (way to many, I bet you can't even count all DBZ games)
Often the game don't live up to the expectations to the fans. But what is your favorite?
Oh, and story must be based of an Anime and/or a Manga. So no pokémon games.
I will go with "Dragon Ball Z Budiokai 2" for ps2.
That is the one I rember I had most fun playing.