Co-Op Games which are fun to play with non-gamer-GF

Dead space 3, awesome coop play. Played the game last week with my gf and it was a blast, took about 11 hours to complete. And one note: she is a GAMER xD

Castle Crashers?

Try Expendabros. If that doesn't work, M&M Clash of Heroes.

Trine 2, Portal 2

Broforce - epic co-op game. Easy to play and super fun.
Oh and + for Portal 2 (mucormucedo suggested)

Serious Sams, Diablos

Saints Row 3 and 4 in general are incredibly fun playing with a friend.

I don´t know, my gf is a gamer, but borderlands 2 isn´t boring in my opinion, especially with three or four players.
You also might want to give Portal 2 a try.

Rayman Legends.

Seconding: Portal 2, Trine 1/Trine 2, Castle Crashers

and adding: BattleBlock Theater, Lara Croft and the Guardian of Light

As others said, Portal 2 can be really fun, but frustrating sometimes. Borderlands 2 is an amazing co-op game, extremely fun.

Nation Red

Pocket Tanks or Crimsonland

Castle Crashers is fun, especially with the pink knight dlc. I have a lot of fun hitting things with my lollipop.

Lot of female friends who don't really game LOVE Little Big Planet.

Portal 2? Magicka?

Thanks for the epic insiders ;) Are there any other games , expect of Castle Crashers, where we can play on the same PC. Hers isnt the best one :P

You probably want something with medium dificulty like Trine 1&2,Portal 1&2 and Lethal League.(not as violent as it sounds,Totalbiscuit has a vid about it and also try to don't completely wreck her and give her a chance)
Edit: also Torchlight

Borderlands 2

Borderlands 2 and Torchlight 2, first and foremost. Then there's F.E.A.R 3, Left 4 Dead 2, Painkiller Hell and Damnation and Far Cry 3. Sorry if that's not what you wanted to hear, but the bets co-op games are FPS. But you can play any multi-player game of any kind. As long as you're on the same team it's kind of like co-op. Best free to play games I recommend are League of Legends and Hawken.

Portal 2, Trine, Magicka, Terraria

Octodad, for real. With randomizing limb control. You'll laugh together a lot as you struggle to get things done. Or strangle each other.

Portal 2, Borderlands (1 and 2), Resident Evil 5 and maybe 6 (5 is better in co-op, and I have a nude mod for it, it was a surprise to me that I found few girls which were interested in it - but they were disappointed after installing mod, because it works only for Sheva), Civilization V (I played once a marathon speed, Emperor difficulty game on a biggest map in Co-Op - great fun, we nuked Russia in 1895, stole entire oil supply from them, and split all their cities between us - we called it revenge for Ukraine) and Metal Slug (especially if you'll find first part - on steam there is only Metal Slug 3 - and it is much more difficult than Metal Slug 1 - which you can't run on PC legally - there is a workaround, but it is illegal)

the main question is: how to get a non-gamer-girlfriend to Play ANYTHING?! #
i can´t even get mine to watch movies that ar for People over 6years....

Sex, best co-op game ever ;)

Some of you wont know what that is, so i suggest you Google it.

Terraria, my girlfriend only plays Sims and Terraria, we have a couple of worlds to play co-op and its really funny.