killbox

The community is decent and well-organized.

Heroes World

Here lies a small problem, and I don't deny that I am also a part of it. For example, long sessions playing turn-based games with people tire me out a lot. But that's not the point, and the problem with mob and similar games is that they have a free structure. It's not necessary to play for 15 minutes and then leave, but you can set aside a certain amount of time for it and continue playing even if someone from the group drops out for some reason. Co-ops clearly require more time than the "play/30 minutes" format, and MMOs are a whole different story. I would try it if there was something decent, but again, I find it difficult to imagine coordinating in them.

Dead Island, Left 4 Dead 2

My favorite (MMO).