UK's Q Magazine has listed the Top 5: Onstage Fights. Included are GUNS N' ROSES and IRON MAIDEN. Click below to read the background:

Guns N' Roses – St Louis Riots, 1991
The mother of all onstage fights? When Axl Rose jumped into the crowd at the Riverport Amphitheater in Maryland Heights, Missouri to confront somebody illegally filming the concert, he couldn't have imagined the scale of the consequences of his actions. What began as a tussle in the mosh triggered a riot that, like Rose's ego some years on, would spiral rapidly out of control.



Iron Maiden – Location and date unknown
Less a scrap than a hilarious stand-off. Somebody in the crowd annoys then Iron Maiden singer Blaze during a performance of The Trooper. Cue mad eyed stares from Blaze during the song, followed by a profanity-filled outburt at the end. "Anyone else?" he asks menacingly? Not us, thanks.

(Thanks Gnrdaily.com)