This is fun. I've seen a heck of a lot of shows going back almost 45 years but I did drop the ball on a few, notably:
Talking Heads
The Minutemen
Pete Seeger
Zeppelin
I've seen Neil but I wish I had caught some of those 1979 shows with Crazy Horse; I saw Lou Reed a few times in clubs but was too late for the Velvets; I saw the Who with Keith but wish I had been at the famous Leeds show; I saw the Clash at Bonds but wish I had seen the '79 tour; I saw Gregg and Dickey and the rest but wish I had seen those early shows with Duane; I saw the Dead in 1978 but, oh man, wish I had seen the '77 tour.... I could do this all night!