Few loops:
If i can say something about it then that one is climatic one
Ghosts of Asgard (http://www.newgrounds.com/audio/listen/370360) by Blueghostsyl (http://blueghostsyl.newgrounds.com/audio/)
More in sf:
RD2010 - Heavy Terror Machine (http://www.newgrounds.com/audio/listen/345935) by alextheDJ (http://alexthedj.newgrounds.com/audio/)
More happy but very good:
-Glorious morning- (http://www.newgrounds.com/audio/listen/91476) by Waterflame (http://waterflame.newgrounds.com/audio/)
Song:
https://www.youtube.com/watch?v=4N3N1MlvVc4
Soundtracks:
Doom soundtrack
https://www.youtube.com/watch?v=CB5WisOOe2w
Blood soundtrack:
CBlood7
https://www.youtube.com/watch?v=Obgl2l1J_8k
But rest of soundtracks of that game is marvelous this one is special
(and in both bloos game's used same soundtracks)
Quake I soundtracks (most creepy music ever):
Only soundtrack from main theme is not soo creepy, all soundtrack from quake was made by Ninch inch nails, but only from first quake.
https://www.youtube.com/watch?v=aaAL-a1pOqs
https://www.youtube.com/watch?v=SFVufWdP4YI
MRtrader sure let me show u this two,
its in some other style but its pretty catchy:
Garden Party (http://www.newgrounds.com/audio/listen/199965) by blarsa (http://blarsa.newgrounds.com/audio/)
and
Triple Gear (http://www.newgrounds.com/audio/listen/75343) by apxn (http://apxn.newgrounds.com/audio/)
Actually i cant find more soo epic and cool like glorious morning. U can always check audio galeries of those guys. With waterflame it will be little hard because he have shitload of audio stuff
Oh and some other most of people should recognize that one :D
https://www.youtube.com/watch?v=KZ2lWyTi0oY
and less known
https://www.youtube.com/watch?v=ROwH8ZEST1U
U can also check most awesome dude ever, if u like majesty of violin then u will love him
Jelonek:
https://www.youtube.com/watch?v=qGEl1d3Zru8