Only been to one unfortunately. I want to/need to go to some more.
Ozzfest 2007, the notorious "Freefest"
Lineup:
Main Stage
Ozzy Osbourne, Lamb of God, Static-X, Lordi, Black Tide
Second Stage
Hatebreed, Behemoth, Nick Oliveri and the Mondo Generator, DevilDriver
Second Stage(Rotating Slots)
Nile, Ankla, The Showdown, 3 Inches of Blood, DÃ…Ã…TH, In This Moment, Chthonic, Circus Diablo