Paper Mario 2 is a must have if you like RPGs, especially if you've played other Mario RPGs. If you like FPSs, Geist was a lot of fun. The ghost aspect was more puzzle solving than anything else though, you don't really get to screw around with it too much. Still, it's worth getting. Viewtiful Joe is great, but since you have a PS2 I would suggest that version since you can unlock Dante from Devil May Cry. SoulCalibur II is great, and you can play as Link in the GameCube version, I would definately recommend it.
I would get StarFox Adventures, but only at a fairly low price. Don't get me wrong, I enjoyed it, but it isn't that much. As for Four Swords Adventures, I'll assume you know the basic info about how it split up into levels and isn't an adventure game. That said, you can have a lot of fun with single player (can use a GameCube controller). the multiplayer mode is where it really shines though, and you need a GBA for each player in that mode. If you have more than one GBA with an adapter or know anybody that does, I would definately recommend it. Otherwise, look for it cheap. The actual Donkey Konga games aren't that great, but Donkey Kong Jungle Beat is a great sidescroller and requires the Bongo controllers. I know that sounds gimmicky, but it's actually really good.
