When Valve used Half Life (1998) to prove that stories can be essential in a gaming experience (and not just something you expect to be there, like in a porn movie), John Carmack must have felt personally attacked, because Doom 3 is HEAVILY focused on story, using a structure that basically copies half life's, both in storytelling itself, and plot.
If Doom 64 was infamous for its heavy focus on horror and creepy ambience, Doom 3 takes it to extreme, being basically an horror game. What manages to impress me, is that it's one of the few games that manages to be scary, without taking the power away from the player, after all, this is Doom, so feeling badass is an essencial part of the experience; your weapons are as powerful as always, but the grotesque enemy designs (which are very... different from the original Doom trilogy designs, but are very welcome, since this is basically a reboot), and absolutely terrifying scenarios always keep you on your toes, but you know, that after all, the only thing they fear is you (at least when you're not using your flashlight)
Most people criticize the fact that you only spend 1 chapter in hell, but c'mon guys, being stuck in a hell infested greyish space station, dozens of millions of killometers away from home, is much more scary.
Absolutely unnaceptable that there is no subtitle, even for BFG Edition.