I don't get the chance to pimp it as much as I should, but everyone that likes Pokemon should give Robopon 2 for the GBA a shot. It's basically Pokemon with robots, a 4 vs. 4 battle system and an amazingly campy story line. It's pretty great.
--
SunnyX ~ The cream of Robopon fanboyisim
http://img217.imageshack.us/img217/5711/flawlessvictorynb4.png