I heard a lot about DayZ and how fun it is. The War Z is a game inspired by the DayZ mod: http://www.thewarz.com/. It's a standalone game that's currently in alpha version. At the time of the writing (12/12/12), you can buy in early ($15 only) and start playing now.
I recently started playing it and it is a lot of fun, especially if you group up with other people. What do you guys think about it? Anyone tried it yet?