Kingdom Hearts would be good, but I doubt that's gonna happen. The GCN controler needs just one more button. Here, lemme show ya:
Most PS2 buttons required has a GCN button equivalent...:
left analog stick=control stick
right analog stick=C stick
control pad=D pad
...but not all of them. See, L1 has nothing. And L1 was a VERY important button to me in Kingdom Hearts. Whadda supposed to do there? There may be ways to work around that, but the experience would not be the same. Besides, it would likely make the game easier or hardeer, and the difficulty it's at is perfect. Changing it would make it worse, even if it's just by the slightest bit. Well, you can't have everything. I have a PS2, though, so why do I care?