Mostly metal/hard rock. Killswitch Engage and Tool are quite possibly the best bands around right now. But I listen to all different kinds except for hip hop/rap, some of the older stuff was good but the new crap is just horrible. I could care less how many houses, cars and gold chains these douches have and that seems to be all they sing about.
Anyways, some examples: NIN, old Manson, Metallica(Black albumn and back), Tori Amos, Amon Amarth, As I Lay Dying, old country(when it was still country), System, Lady Gaga, Trance/House techno, Five Finger Death Punch, Trivium, Foo Fighters, Black Tide, H.I.M. and many many more.