Many of the best have already been noted. I'll add:
Feelies
Todd Rundgren (on a good night, there have also been some bad ones)
Rebirth Brass Band
Dirty Dozen Brass Band
Kid Creole
Gatemouth Brown
Fleetwood Mac/Lindsey Buckingham
Zachary Richard (when he was legal and Sonny Landreth was aboard)
Smithereens (loud!)
The Bongos
Richard Thompson
Among others
Feelies
Todd Rundgren (on a good night, there have also been some bad ones)
Rebirth Brass Band
Dirty Dozen Brass Band
Kid Creole
Gatemouth Brown
Fleetwood Mac/Lindsey Buckingham
Zachary Richard (when he was legal and Sonny Landreth was aboard)
Smithereens (loud!)
The Bongos
Richard Thompson
Among others