Probably Mastodon on the Crack The Skye tour. They played every song I was hoping they would, was front row for all of Mastodon (caught in moshes for most of the openers), the lighting and sound were excellent, the crowd was amazing, was loud but not too loud to not wear plugs, and I had a lot of "moments" with most of the members. Not to mention I couldn't get enough of this band at the time. Also, all of the openers (still not a fan of Between The Buried And Me though) kicked tons of ass and were just great music and put on a good show!
Another would have to be Metallica. They put on an amazing show, and I was still obsessed with them at the time (I had like a two year phase that was almost nonstop Metallica) and it was just an amazing experience. But Mastodon topped it in almost every area.