i could make a huge list about this, since most of the stuff i listen to , barely anyone listens to. but most are old-ish and some of them were popular once.

http://www.youtube.com/watch?v=HBMvUpBrWFQ&list=FLJFDr_H9S-lc0rLzN8J4sew&index=43 <--- this guy was pretty popular back in the 80's

http://www.youtube.com/watch?v=bp-qt5gRqA4&list=FLJFDr_H9S-lc0rLzN8J4sew&index=8 <--- same here about these two

http://www.youtube.com/watch?v=NCMm1mJ3DRs&list=FLJFDr_H9S-lc0rLzN8J4sew&index=37 <---- this kind of music is an aquired taste,not everyone likes it, but be sure to listen , its very atmospheric.

http://www.youtube.com/watch?v=Jh9HVvFNOyA <--- Very folklorish type of music

http://www.youtube.com/watch?v=ROnXv7Z7v28&list=FLJFDr_H9S-lc0rLzN8J4sew&index=182 <--- this was popular in the 80's in the Gothic rock scene as well

http://www.youtube.com/watch?v=QEpW4mLHN60&feature=related <---- same as above

http://www.youtube.com/watch?v=SHXOWwqwPDo&list=FLJFDr_H9S-lc0rLzN8J4sew&index=6 <--- this is an OLD heavy Metal band that i don't really know why they don't get much attention , they're fantastic.

http://www.youtube.com/watch?v=wWvfvZTQODE <--- this is one of my favorite songs,be sure to listen to the lyrics.

http://www.youtube.com/watch?v=Bk8W3ysnB7M <--- this is very experimental , you might not like it, but its actually the sound director of the infamous games , you will notice the similarities

http://www.youtube.com/watch?v=MByVLThpfDw&list=FLJFDr_H9S-lc0rLzN8J4sew&index=110 <--- really good Industrial Music, (PS Psycho Mantis included xD )  this kind of music is the reason why "Dubstep" sounds so whimpy ,boring and out of distorsion.

http://www.youtube.com/watch?v=SVNjx4k8mWk <--- same as above, but i think they're pretty popular industrial band, , i don't really know.

http://www.youtube.com/watch?v=EQJUUDsfRek <--- these are one of the best bands of their genre "Doom Metal" , its pretty close to Death metal without the "death howls" but rather more atmospheric and melodic.

http://www.youtube.com/watch?v=NP9tFZlmAXQ&feature=relmfu <--- Ayreon ... is just great, listen to them! , they're not really a band, but rather a collaboration of many known musicians  in the Metal genre (EX from Dream Theater , Opeth ...ect) , the result is some great one of the kind music

http://www.youtube.com/watch?v=YY-EOYJQMMY <--- this is symphonic metal at it's best, they're pretty popular though... but the genre itself isn't popular

http://www.youtube.com/watch?v=3i7H1--JxVw&ob=av3e <--- if you guys love Heavy Metal, and wonder "There is no good metal bands anymore!" , well i got bad news for you , you are looking at the wrong place.

PullusPardus said:

[...]

http://www.youtube.com/watch?v=YY-EOYJQMMY <--- this is symphonic metal at it's best, they're pretty popular though... but the genre itself isn't popular

[...]

I kinda liked :

John Foxx,  Music is aweomse but once he sings my excitement goes a bit down lol. Bookmarked to check more songs.

wumpscut - war, the video quality is creepy though :/

that wumscut video is fan made, and the crappy quality in intentional, as for the rest, like i said its an aquired taste.