Just a heads up for stealth gameplay fans, the standalone version of Doom 3's "Dark Mod" was released just yesterday.
In a nutshell, it is a Thief remake in a modern engine.
Their site,
http://www.thedarkmod.com/ is currently down from all the traffic they've been getting so if you want to give it a try, use the torrent from here:
http://www.moddb.com/mods/the-dark-mod/downloads/dark-mod-20-standalone-torrentRecommended!
PS. If you're using an ATi card, install Radeon Pro tool and use it to tweak the 3D settings. Give AA and AF control to application (no driver overrides) and turn of VSYNC. Best of luck!