I posted a list here before:
Fun Lovin Criminals (2002) (Don't like them to be honest. They came to my school after some competition or something like that.)
Stone Sour (2003)
Saliva (2003) (Supporting Stone Sour)
Steve Vai (2004) (G3)
Joe Satriani (2004) (G3)
Robert Fripp (2004) (G3)
Anthrax (2005)
Black Label Society (2005)
Meldrum (2005) (supporting BLS)
Velvet Revolver (2005)
The Ga Ga's (2005) (supporting VR)
Biffy Clyro (2005) (supporting VR)
Mot�rhead (2005)
In Flames (2005) (supporting Mot�rhead)
Girlschool (2005) (supporting Mot�rhead)
Dragonforce (2006)
Edguy (2006) (supporting DF)
Sabaton (2006) (supporting DF)
Saxon (2006)
Blitzkrieg (2006) (supporting Saxon)
Armored Saint (2006)
Deep Purple (2007)
Styx (2007) (supporting DP)
Thin Lizzy (2007) (supporting DP)
Steve Vai (2007)
Zack Wiesinger (2007) (supporting Vai)
Rush (2007)
Dream Theater (2007)
Symphony X (2007) (supporting DT)
Porcupine Tree (2007)
Anethema (2007) (supporting PT)
Mars Volta (2008)
Diamond Head (2008)
Opeth (2008)
Arch Enemy (2008) (Co-headlining with Opeth)
DevilDriver (2008) (Supporting Opeth/Arch Enemy)
3 Inches Of Blood (2008) (supporting Opeth/Arch Enemy)
Blitzkrieg (2008)
Upcoming:
Metal Camp 2008