ZZ Top a little over 2 years ago. I'd seen them before and they were amazing. We had great seats, but that was part of the problem, the sound system wasn't tuned right for the front seats, so if you didn't know the songs, you'd have no idea what Billy Gibbons or Dusty Hill were even singing.
We also had some really obnoxious drunk people around us, and they played for less than an hour, with a two song encore if I remember right, granted they are quite a bit older now, I still expected a longer show.
I told a friend after it was over, that will probably be the last concert I ever attend. It was just too loud, and the other people were beyond annoying. It just wasn't worth the various headaches afterwards.