I think for quick fun games, you might enjoy something arcade like. RPG has too much depth for casual interest. RTS requires developing skill and practice. FPS is possible if you like that sort of thing.
Do you want a game where you compete against your partner, or cooperate with him?
Do you want to take turns, or be playing simultaneously?
Do you want guns and ultraviolence, or flowers and bunnies?
Do you want a game that uses your mind, or uses your reflexes?