I'm a power metal fanatic (e.g. Blind Guardian, Iced Earth, Stratovarius, Demons & Wizards, Dragonforce), but I'll listen to all other metal subgenres as well (excluding nu-metal, but that goes without saying since it isn't a real subgenre of metal), especially heavy and progressive.
Some of my other favorite metal bands:
Iron Maiden
Black Sabbath
Judas Priest
Metallica
Slayer
Edguy
Bathory
Circle II Circle
Dream Theater
Symphony X
Goat Horn
Kamelot
Nevermore
...and I'll stop there, for now.
I'm right psyched for the new Stratovarius and Blind Guardian albums; they shall be great.