Fast paced shooty stabby jumpy freedom fun. Gets even more crazy with friends. Has both local and online co-op multiplayer.

Features such as simultanous turns and play by e-mail makes this turn-based strategy very easy and painless to play with friends.

Search the steam workshop for "Secret Hitler" or "Exploding Kittens" and enjoy hours laughing with your friends. SUPERFIGHT DLC is every good as well.

Really fun racing-platformer: great steam workshop support, local and online multiplayer, and addicting mechanics.

Fantastic karting game, you can play local co-op/competitive on any aspect of the game including the "singleplayer" campaign.

Super fun one of a kind co-op RPG. Great characters, great dialogue, fun mechanics, and a very nice user interface.

The noise, the panic, the chaos...the question is: are you and your friends up to the task? Microphones are recommended.

Great local co-op game, even better with mods. No online multiplayer though, and it requires a controller for local co-op.

Great babies first grand stratagy, good for getting friends into the genre.

Slow, but awesome real time stratagy for those late nights when neither of you are fully functioning. Don't be surprised when it's suddenly morning.