18 Left 4 Dead 2
In most survival horror games, zombies are a pesky nuisance at best, and a temporary obstacle at worst. Left 4 Dead 2, featuring gruesome goons like Hunters, Tanks, and Chargers, will reacquaint you with your itchy trigger finger in a hurry. In this co-op first person survival marathon gone mad, the Infected will chase your motley gang of Survivors with all the gusto of Olympic track runners, and having as many players as possible behind the controllers is indubitably the best way to survive. If you missed the previous Left 4 Dead, get ready to experience one of the best story-driven horror series on shelves now. Oh, and trust us, you don't want to startle the Witches.