Left 4 Dead 2 is a total blast from the past, especially for those who love mowing down hordes of zombies with friends. It's a simple concept – four survivors gotta work together to survive a crazy zombie apocalypse. The campaigns are fun and frantic, the different special infected keep you on your toes, and there's tons of replayability thanks to the random Director AI that tweaks things up each time. The graphics might be a bit dated, and the lack of a story is a bummer, but for pure, chaotic co-op zombie slaying fun with friends? Left 4 Dead 2 is still one of the best out there.