I've seen a lot of great shows: The Who performing Tommy at the Commonwealth Armory in Boston in 1968, Traffic at the Boston Tea Party in 1969, Woodstock later the same year, Springsteen countless times, Dylan and the Band at the Boston Garden in 1972. Some famous ones that although famous weren't necessarily great: the Beatles at Shea Stadium in 1965.
The one that got away was The Band over four days at the Brooklyn Academy of Music at New Year's 1971-1972, resulting in Rock of Ages, perhaps the best live album ever before Springsteen's Dublin concert with the Seeger sessions band.
Today, when the UPS driver shows up, he'll be bringing a brand new release, 4 CDs and 1 DVD of that magical weekend in Brooklyn long ago.
Here's a taste of Robbie, Garth, Levon, Rick and Richard from that weekend: http://www.youtube.com/watch?v=11Y987Uf1wY