I only recently discovered “Doom Metal” and I like it a lot. This music is too epic to be depressing.
A bit of a description from Wikipedia:
Doom metal is an extreme form of heavy metal music that typically uses slower tempos, low-tuned guitars and a much “thicker” or “heavier” sound than other metal genres. Both the music and the lyrics intend to evoke a sense of despair, dread, and impending doom.
This album cover for Candlemass’ Nightfall (a well known example of the genre) is incredible:
Anyway, give this a listen to someday. The whole album is on Youtube.