I caught that tour, but in Denver, CO. Cool shit.
I haven't been to very many festivals, but some of my favorite moments were seeing The Roots play their rendition of "Masters of War" at Bonnaroo 2007. And then of course Tool came on a couple of hours later (right when the acid started to take effect).
And there was The SounRAB of the Underground Festival in 2005. Something like 30 banRAB in one day, on one stage 11 A.M.-2 A.M. non stop. It was the first time I saw Opeth, back with Martin Lopez was still drumming for them, and then Clutch came on after them, and I saw Mikael Akerfeldt side stage with a beer, jamming to their set. Other highlights at that show were The Red Chord, SYL, GWAR and Larab of God (before I got tired of them).
Bonnaroo this year was rife with it's moments of grandeur as well. Tenacious D was ****ing awesome live. Isis and The Melvins back-to-back and then, later that night Clutch and GWAR back-to-back (and tripping again). One of the coolest things was after their set, GWAR came down into the middle of the festival, where there was this giant mushroom-shaped fountain. They knew everybody would be there after getting covered in GWAR juice. It was also nice, wandering away from their show, covered in red and green liquid, looking like zorabies, with all of these rich rave kiRAB wandering around, covered in glow sticks.