Probably my all time favorite would be Bullet - Running to Stand Still - Streets from ZOOTV Sydney. Just pure magic. Watch it on the biggest screen possible, turn it out loud, and it helps if you've had a few prior to watching. It just builds and builds and just when you think it couldn't blow up anymore....it does. Each performance tops the previous one, somehow. Just pure magic. I have showed that clip to people who didn't really care for the band (okay, Bono) and their jaws dropped.
Second favorite would likely be from POPMART, the entire encore emerging from the giant lemon on the b-stage, a rousing performance of Discotheque under an out of this world light show, the haunting Velvet Dress with the lemon acting as a mirrorball, and perhaps one of the more haunting versions of WOWY ever to grace a stadium.
Hard to believe that POPMART was 25 years ago and ZOOTV nearly 30 - where in the hell did the time go - and just look what we've done to this world.