Doom 3 is tight but trust me, coming from a 13-year ID Software hardcore fan... Quake 4 blows Doom 3 away. It uses the same engine, its just better in every way. Doom 3 is alright, the single player is fun to beat, but once you beat it you probably wont play it again.
Quake's where its at. Anyone played it for the 360? the deathmatch is high speed and action packed as fuck