I've been playing Vermintide recently, which is basically Left For Dead in the Warhammer setting, with Skaven (that's rat-men) instead of zombies. Despite some extra bells and whistles, it's pretty mindless, but it works well and the graphics look excellent (my excuse is that I'm researching how to make model buildings). The Skaven all sound like Gollum when angry, and the characters are suitably over the top (the wizard, who sounds like an angry grand dame of the theatre, is my current person). Decent stuff. The only bad thing is that you can't play it offline, even if you're on your own.