I guess one could label me as a metalhead, though I listen to a lot more of the mainstream metal than Altmer. I really love the bluesy and supremely heavy metal recorded by Black Sabbath, and the bands that try to continue that (Sleep, Electric Wizard). Apart from that, just good old thrash metal: Metallica, Megadeth, Pantera, White Zombie, Testament.
I never could get into Slayer, actually. I hear great things about them all the time, but I think it's just too extreme for me. I want to be able to get into the song and headbang or something but even my ears and brain can't keep up with Slayer's ridiculous tempos. I never could really get into power metal either, because when you listen to one or two songs, it's great, but it gets boring to try to listen to the whole album.