Kingdom Hearts: Chain of Memories. Yes the GBA one! I played that and KH2, I think both are fun, but KH2's fighting is too simple to me. I will be hunted down for this statement because people hate the card system. I claim that KH2 is too easy because you only ever need the attack and reaction commands. Magic and Drives are extra and I never see anyone else use magic unless they want some mini-game record, while Drives are massively fun but almost unnecessary. (I still want to play KH1!)
Edit: And for the record, I made very good use of the cards. Only took a bit of getting used to at the start.