I love this community, got so many recomendations I decided to update the first post! Sorry if I couldn't reply to everyone, Jerboa almost exploded, haha. But I'll upvote all your contributions now that I'm on PC.
Original post
I like to play on the same computer with my bf, and recently we've started to get tired of MAME since we've been playing our faves on repeat for so long.
The other game we play is Spelunky, since is the only local co-op game I have on Steam. I ask because Steam summer sales are close and I can give him a surprise :D
Magicka - top-down mage play where you can combine spells with each other (two beams make a stronger beam, etc), and friendly fire if you want to occasionally nudge or troll each other
Trine - side-scroller in 3D graphics with 3 unique characters; some platforming, action, and slight puzzles, and a very good story presentation/direction