Regret Slayer having to cancel one of their shows on the Jager tour back in '04 I believe when they had KSE & Mastodon. Back when KSE was still somewhat respectable plus I had to wait till Mayhem last year to finally see Mastodon. I still remember having that ticket in my hands...
Oh and Velvet Revolver in KC. It was only the 2nd show that they ever played. And of course they did several G 'n R & STP songs. Fuckin friends and their weddings!!!!!!!!!