I am proud to have seen Strapping Young Lad on their last tour ever on Ozzfest 2006, but it pisses me off to an extreme extent that I, at the time, had no idea who any of the bands were on the entire festival except for BLS and Ozzy...
Today SYL is one of my favorite bands, and it drives me insane that I've seen them before.... I would kill to be able to see them now.
Also I saw Black Sabbath on what is probably going to be their last ever tour with Ozzy, which was Ozzfest 2005.
And Opeth of course.
I've lost track of just about everything.