U2 (3 times, BEST CONCERTS EVER!!)
No Doubt (1 ND concert, saw them open for U2 twice if that counts)
Maroon 5
Barenaked ladies (2 times, one was a free concert for the Olympics)
Train (free Olympic concert)
Kenny Chesney (w/ Uncle Kracker and some others I can't remember )

I can't remember, I may be missing some...I don't go to concerts often, I don't have much money to spare...UNLESS it's U2!!