U2 - Oakland Arena

Totally mind blowing.  I had shown up at the arena without a ticket and managed to buy one for a reasonable price (with some help from Rome) from a scalper after the opening band (don't remember who it was) had finished.  I walked onto the floor right before U2 started their set.  It had been 9 years since I'd last seen U2 and I wondered why it had been so long.  9/11 was still fresh in everyone's mind, making for a particularly emotional and spiritual experience.