Ah! Metalheads UNITE! *horns*
But yeah, like my comrade @Rawzy I am really into; especially recently as I've been trying to branch out into other subgenres like doom metal, death metal, melodic death, metalcore, and even some black metal with bands like Amederia and Hyperion. That said, my favorite genres tend to be power metal, symphonic, and progressive with bands like Rhapsody of Fire, Sonata Arctica, Galneryus, Unleash the Archers, Orden Ogan, Twilight Force, Olympos Mons, Epica, Kamelot, Therion, Nightwish, and others typically being ones I go to. My favorite, however, is Symphony X who started with progressive elements with a lot of their more recent material being a bit more heavy.
Aside from metal artists, I typically love anything classical, with artists like Igor Stravinsky, Sergei Prokofiev, J. S. Back, Mozart, Beethoven, Wagner, and others being amongst my favorites. And to expand with the orchestra, I love film/TV/game scores as well; with James Newton Howard being my standout favorite.
When it comes other styles of music, my favorite artists are Streetlight Manifesto (punk/ska), Tech N9ne (rap), Marty Stuart (country), and Ian van Dahl (trance).
Of course; the greatest singer of all time; Frank Sinatra! <3