For me it was Depeche Mode. They were so awesome, they were ALL over the stage rocking out. Then I saw them again about five years later and they barely moved, sort of a bummer. Madonna was pretty awesome too. I also saw AC/DC but didn't really like it too much.
I really want to see Prince, Killers and Pink Floyd. Prince just had three shows at Nokia Center this past weekend, but I had tickets for something else. I also turned down a chance to see Pink Floyd, bummer. Plus the old Michael Jackson would have been good to see live, too.
Going to see Coldplay, I'm looking forward to that!