This definitely ranks as one of the best games I've ever played. Not quite up there with the Fallout series, but very close. this game should be at least a runner up to Game of the Year. Scary as a hot place south of heaven (language rules), intense, challenging and fun. The game also really draws you into the lives and personae of the characters. Far more cerebral than a typical zombie "run and gun" game. Without giving away the ending, you'll find your heartstrings tugged in ways you didn't think possible from a video game.
I liked it so much I bought it to coin a popular cliche. I recommend this game to anyone and everyone including those of you who think you don't like zombie games. Take my word for it, play this game and if I'm wrong go ahead and flame me in the comments...I bet you'll be thanking me instead.