Best concert I went to was a 3 day concert called Livestock which is in the middle of nowhere and you basically setup camp for the 3 days. The lineup was as follows:
JOE SATRIANI, DISHWALLA, SELF, INTO ANOTHER, DRIVIN' N' CRYIN, SUGARSPOON, KORN, I MOTHER EARTH, TRIPPING DAISY, THE HAZIES, LIFE OF AGONY, MEN FROM EARTH and many local bands from the Tampa area.
Another concert I enjoyed was Radiohead with opening band 'Liars' at an amphitheater in West Palm Beach, Fl. These venues provide spectacular sound!
A friend asked me to go to a Crosby, Still, Nash, and Young concert like 10 years ago. I wasn't thrilled about going but for them being old guys, they jammed for over 3 hours, 1/2 electric and 1/2 acoustic with just a 15 minutes break. It was fooking brilliant!