Now this I can do
Iron Maiden vs Iced Earth
Pantera vs
Deep Purple
Blind Guardian vs
Judas Priest
Tool vs In Flames
Lamb Of God vs
Testament
Pink Floyd vs Guns N Roses
Death vs Pig Destroyer
Anthrax vs Metallica
King Diamond vs The Scorpions
Nocturnal Rites vs
Venom
Blaze vs Converge
Hallow's Eve vs
Voivod
Morbid Angel vs Heaven & Hell (WTF? This shouldnt even count)
Dio vs Kreator
Dream Theater vs
Vio-Lence
Cro-Mags vs
Opeth
Rod Halford vs
Slayer
System Of A Down vs
Amorphis
Grave Digger vs
Motorhead
Nightwish vs
Helloween
Velvet Revolver vs
Megadeth
Black Sabbath vs Mastodon
Savatage vs
Led Zeppelin
Rage Against The Machine vs Winter Sun
Children Of Bodom vs Killswitch Engage
ACDC vs Masterplan
Evergrey vs
Overkill
Queensryche vs Amon Amarth
Gamma Ray vs Kamelot
Rush vs Manowar
Stratovarius vs Symphony X
Edguy vs Sepultura
Hardest choice was Mastodon vs. Sabbath. If Mastodon keep going the way they are now though they'll take that spot soon enough.