Ok so far I've seen Iron Butterfy, Black Sabbeth, Deep Purple, Zep., AC/DC and others, but you guys have barely scratched the suface!! You didn't even mention Iron Maiden, the godfathers of metal, along with Slayer, Juddahs Preist, Pantera, Lamb of God!!!! All That Remains, At The Gates, Celtic Frost (don't let the name fool you, they are deff. not celtic metal, however that would be cool.)
Venom, Guns N' Roses, KoRn, DIO!, KISS, Megadeath, Metallica, Motor Head, Ozzy Osbourne, As I Lay Dying, War Saw, Pestilent Chior and I havn't even listed them all!