I know there may be some debate over which sub genres exist and which don't but I think I made the most non-controversial list I could.
My vote goes to heavy/traditional metal. Just to name the obvious ones, Iron Maiden, Dio, Black Sabbath, Judas Priest, Blaze Bayley, Ozzy, King Diamond.
You can't go wrong. Not to mention stuff like Zep, Motorhead, and Rainbow sometimes get thrown into that category. Now I personally don't agree with that, but I ain't gonna complain.
Edit: If you think I should include grindcore, tell me and I'll edit it.