I was actually talking about this the other day. To me doom 3 was an amazing game.
pro's:it broke the mold on how it told its story, it was VERY original, at the time it came out it got a LOT of flack for it being unrealistic. i mean who would send video/voice and files to a phone? ridiculous. I saw the genius of it, and loved it for thinking outside of the box. That isnt very common in any game, let alone a FPS. Their was a lot of details...and those damn demon scorpion cherub baby things were freaky as hell. Like seriously the first time i saw one i was like awww its so cute. AHHH its attacking AHHHHHHHH. yeah great times. Even better i had a group of friends watching me play over my shoulder and the comments/conversation about those things was epic.
Cons: really only one, the level design/spawn became predictable. Lot of other games with this flaw as well, so cant hammer it to hard for this. considering they hit everything else on the head (controls, graphics, story, etc) i can forgive it to me its one flaw.
Bonus Pro: This game is the best game with rocket jumping since TFC.