I've put off joining the party for a while, but I think it's about time I entered into the 'Hell itself. I mostly listen to rock music of all sorts: Alternative rock, grunge, "indie" rock, hard rock, progressive rock, acid rock, "classic" rock, and rock n' roll - but I have to say that Heavy Metal is the kind I like and listen to most, without a doubt.
My musical 'taste' didn't really develop until I was about 14, when I discovered music that was unlike the kind everyone else I knew listened to (it was either commercial rap or 'Regional Mexican'). I liked this new sound and began to look for other things that sounded like this. Eventually, as I grew older, my interests broadened significantly and I can say that I enjoy (or at the very least, tolerate) all forms of music - even the dreaded country genre. To be entirely honest, my most favorite kinds of musical styles are, in order - 1.) Braindance, 2.) Heavy Metal, 3.) Industrial, 4.) Alt. rock, 5.) 'classical' music.
As for bands and types of Metal I listen to, it's mostly the 'traditional' Heavy Metal type with some speed/thrash and the occasional nu-metal or alt. metal bands. A quick look at my library categorizes these artists as "metal" and I happen to like and listen to them often:
Black Sabbath, Metallica, Iron Maiden, Slayer, Testament, The Deftones, Slipknot, Faith No More, Pantera, Anthrax, Disturbed, Korn, Megadeth, System of a Down, Cradle of Filth, Strapping Young Lad, Judas Priest, Motorhead, Lamb of God, and pretty much every major industrial metal band.
I also wish to learn more about death metal, 'grind' styles, power metal, and prog. metal, as some of the material I have heard out of these areas are lacking in my library and I am interested in listening to more of it. I guess what I meant by that last statement is: where should I start if I wanted to get a better taste of each of these styles and considering my exposure, what would you recommend?