This is all kinds of fun to read! My worst concert experience was Linda Ronstadt at the Erwin Center in Austin. Not because of her, she was red hot. But in those days, the sound in that place was ear-splittingly loud. It completely ruined the show. Everybody was trying to plug their ears. This was during her punk or new wave period.
My best experience was seeing the next to the last Beatles live show at Dodger Stadium in August, 1966. I got the ticket by sending an air mail letter to my sister in L.A. with 3 one-dollar bills in it. Their show lasted only 33 minutes, but I'll never forget it. The sound was crystal clear, and you could hear it over the screams.
When we got to the stadium, a girl was standing by the front gate, holding a Beatles picture and crying. No ticket, I figured. After the show, she was standing in the same spot, still holding that picture and crying. For all I know, she may still be there!