The music I enjoy most is metal. Here are some of my favorite sub genres and some bands to go w/ those:
heavy/classic metal - Iron Maiden, Judas Priest, Motorhead, Manilla Road, A Sound of Thunder, Artizan, Grim Reaper, Enforcer, Riot
power metal - Helloween, Iron Savior, Lost Horizon, Iced Earth, Jag Panzer, Kobra and the Lotus, Triosphere, Dream Evil, Rage, Cage, DragonForce, Twisted Tower Dire, Falconer, Neonfly, Firewind, Nightwish, Striker,
death metal - Death, Vader, Morbid Angel, Septicflesh, Immolation, Atheist, Bloodbath
black metal - Immortal, Rotting Christ, Melechesh, Emperor, Dissection, Mare Cognitum, Hail Spirit Noir, Sigh
doom metal - Candlemass, Pentagram, Argus, Esoteric, Ahab, November's Doom, Triptykon, Avatarium, Blood Ceremony, Reverend Bizarre
thrash metal - Overkill, Exodus, Megadeth, Anthrax, Death Angel, Kreator, Gama Bomb, Metallica, GWAR
stoner metal - The Sword, Clutch, Electric Wizard, Mustasch, Fu Manchu, High On Fire, Sleep, Corrosion of Conformity
sludge metal - Neurosis, Isis, Mastodon, Intronaut, Minsk, Baroness
metalcore - Converge, Protest the Hero, Walls of Jericho, Trivium
Other than this I like a fair bit of psychedelic rock, progressive rock, downtempo, industrial, classical and jazz as well. Here are some examples: Yes, King Crimson, The Mars Volta, The Beatles, Pink Floyd, Marillion, Cream, Boards of Canada, Pretty Lights, Shpongle, Entheogen, Nightmares On Wax, Aphex Twin, The Orb, Miles David, Return to Forever, Mahavishnu Orchestra, Weather Report, Grateful Dead, Skinny Puppy, and VNV Nation.
There's SOOOO many more I could've added to all of this but I'll leave it at that for now.