That Phase 1 coming was one of the best things ever in a game also. I remember me and a friend trying to play it together over the phone and I stumbled across him first. It scared the crap outta me. I dropped the phone and the batteries flew out the back.
I was still living at home when I played this and when my parents heard me should "F*CKING HELL" they thought i'd badly hurt myself or something and came in to see what was the matter. Good times
Doom was pretty scary, but in a more grotesque horror rather than suspenseful. The one thing that made Doom scary was the sound - you could here a Cyberdemon for ages before you saw it and when it did appear it was like:
"Oh Shiiiiiiiiiiiiiiit!" as you run away backwards empting all your ammunition into it. This was quite a regular occurance though. With Dark Forces, you heard the noises of the Dark Troopers through the breifing on level 2 and it gradually built up the suspense over several levels until BOOM!
This metal endo-skeleton thing with glowing red eyes and a massive blade comes jumping at you, your blaster fire just bouncing off his sheild as you run away from it, frantically trying to find the key for the rocket launcher. Good stuff!
I liked MoTS a lot, especially towards the end in the Sith temple - completely dark (in atmosphere as well as literally) - you get a true feeling that this is someplace evil and completely impregnated with the dark side.
That for me was one of the biggest let downs in JA - the final mission on Korriban and its the old mausoleam [sic] of Marka Ragnos AND IT'S A NICE SUNNY DAY! Hardly suspense building!
But back on topic - I love Star Wars, DF drips in SW atmosphere and therefore I do prefer it.