^ Amen. FEAR shouldn't be played because someone tells you its scary. Because its not. Not in the least bit. However, what you SHOULD play FEAR for is the visceral experience. Its simply got the MOST INTENSE firefights I've ever seen in any FPS till date, and the AI is just top notch. Sure, the level design in bland, enemies and weapon design are pretty dull, and the scare factor is minimal at best, but once you get into a firefight, the game will have your adrenaline pumping through your veins like none other.
As for Doom3, meh. Q4 was a lot better, and visually, a helluva lot more stunning, but nothing compares to FEAR in firefights. Prey is great, but pretty short and a good run-of-the-mill shooter, thats about it.
If your PC can make FEAR look pretty, (at least a 6800/X800 series card) then by all means, go for it, its an experience you will never forget.