The problem with Doom 3's gameplay is it was too fucking dark and constantly having demons jump scare you or spawn behind you got stale quickly. At some point I need to give the BFG edition a try which at least addresses the "too fucking dark" aspect, but that's also now a 2012 game instead of a 2004 game.

The quality of gunplay (sounds, feedback, enemy reactions) is a surprisingly big, yet underrated part of an FPS. Far Cry looked great but was hard to enjoy as the gunplay was crap. A big reason why Quake 2 was so popular was that the super-shotgun, rocket launcher, railgun and BFG felt amazing in their own unique way.