You should get Frogger Advance. I've got a lot of ROMs for the GBA, and they're all pretty good. I'm an old game fanatic, so that;s probably just me. Go to CoolROMs and just try some out. I'm sure you'll find something good.
DBZ Legacy of Goku DBZ Legacy of Goku 2 Megaman Battle Network series (especially these. there's six of them, and there are different versions of 3-6, so that should keep you occupied for a while. They also have a beautiful storyline.) Megaman Zero series Castlevania: Circle of the Moon the Pokemon series