I haven't thought of any specific games right now, but I wonder if you might find anything at this site:
http://dragonphoenixgames.com/friends-and-lovers/
This is a site where some people have taken a bunch of popular games and created co-op versions of them. I admit, I haven't actually tried any of them yet, but it sounded like an intriguing notion, and might expand the range of possible titles for your criteria.