You've gotta hit up Civ 5
Old favorites were Legend of Zelda and SMB3.
I don't know why it is, but MarioKart 64 was/is superior to any other version that came out, and arguably my favorite game ever. I and four friends (loser was out next round) spent an entire weekend holed up in a room playing that game.
I wanted to pick up The Last of Us as so many have mentioned it and I've heard it's good, but I have a 360.
I sold it a few years ago but here is one I built