Ok lets see... I'm going to try and limit myself:
Aborted, AMON AMARTH, AMORPHIS, Anathema, Ancient Rites, Antichrisis, ASGAROTH, AT THE GATES, Carcass, Control Denied, Cynic, Dakrua, DDT, DEATH, Dimmu Borgir, Dream Theater, ETERNAL GRAY, Evergrey, FEAR FACTORY, Gordian Knot, Hammerfall, HELLOWEEN, LACRIMOSA, Laibach, Metallica (Old), Moonspell, MR. BUNGLE, Nightwish, NoFx, NOKTURNAL MORTUM, Obituary, Opeth, ORPHANED LAND, Pantera, S.O.D., Salem, Samael, Sitra, Sodom, SUMMONING, The Beatles (Not metal but definitly guilty), The Police, Therion.
There are some more I didnt put cuz I just didnt remember. Oh well, lucky I didn't do a vertical list, ha?