sethnintendo on 21 June 2011
I just typed good co op games for PC and got this link..
http://www.co-optimus.com/system.php?id=4&page=0
It seems to have some very old games on there also (I just saw Hexen). Although I did notice it says Duke Nukem 3D had co op campaign available online... I never knew that considering I never belonged to the TEN game network (I think that is what it was called). I just played 1v1 against my friend on 28/56k modems back in the day.
Seems to be a decent site and tells you if there is co op modes, co op campaigns, etc...
