I think the original FEAR is one of the finest FPS games ever produced. The pacing of calm vs. fighting vs. scary vision was just right, the particle effects are still some of the best produced, the speed & weapon damage of combat is just right. The storyline is a bit OTT, but as stated earlier it doesn't matter if it was presented well, which it was.
FEAR did tense gameplay properly - not "BOO!" scares like Doom3, but more painfully tense anticipation of action as you're creeping around.
Though that big fat redheaded pig bastard really pissed me off. The game didn't really need comic relief, and that guy just wasn't funny.
Dead Space is quite a good game... but it doesn't compare to FEAR for both storyline presentation (hi dead lady, bye dead lady, hi dead lady, bye dead lady, oh snap someone stole the shuttle, sucks, oh snap I just cut off some dead baby's tentacles). Think I'll start up both a FEAR and Dead Space campaign.
ALSO Dead Space suffered from really fucking absolutely terribly horrible consolitis in the technical areas. V-Sync was a mess at release, sensitivity was busted (related), reproducable crashes when using your map in an elevator with an overclocked 8800GT, and worst of all: keyboard/mouse input was run through an analog controller emulator. That's unforgiveable. Still a kickass game, FEAR was just more of a grownup's game.