I'd recommend Chrono Trigger/Earthbound/Super Metroid like others have, but they're bound to be expensive. Apologies for the illegality and everything, but why not just play them on an emulator?
The advantage of using the actual console is, y'know, controllers and playing on the TV in the living room and stuff. Comfort. So buy some multiplayer games, and either get your dad to revisit his college days with ya, or turn your friends on to some old-school awesomeness. Mario Kart is great, but you've got that already, so:
F-Zero, Star Fox, Secret of Mana, Contra 3, Zombies Ate My Neighbors.