With the success of Fallout 3 and Borderlands, videogame developers are beginning to listen to postapocalyptic lovers and their request for more games in a PA setting. Metro 2033 is a new first person shooter coming out in the next month or so that puts you in future Moscow, where the world has been destroyed by one form of war or another.
According to a video game blog I went to, Metro 2033 is based on a cult novel of the same name, and has you take the role of Artyom as you go into the Metro system of the future, to warn the remaining survivors of yet another impending threat.
Here is the latest trailer I was able to dig up. It looks pretty good:
