Can’t pick the "best" but some memorable ones:
--Grateful Dead Nassau Coliseum 9/8/73, I was 15 years old and my first concert. General admission, sat roughly 15 rows back on the floor. (Dave’s Picks #38)
--Genesis doing the Lamb Lies Down on Broadway-- on Broadway!! 12/7/74 at the NY Academy of Music. 11th row.
--Little Feat at Wesleyan University, 4/4/78. General admission, was one of the first in line, leaned up against the stage in front. Could basically lean over and grab Lowell George’s leg I was that close.
Saw several great Grateful Dead shows-- many of which they have released:
6/17/76 at the Capitol Theatre in Passaic, NJ (Dave’s Picks #28)
4/30/77 at the Palladium in NYC (Download Series Vol. 1)
5/4/77 also at the Palladium
5/5/77 at the New Haven Coliseum, CT (Get Shown the Light)
5/28/77 at the Hartford Civic Center, CT (To Terrapin)
5/10/78 at the New Haven Coliseum, CT (Dick’s Picks #25)
5/11/78 at the Springfield Civic Center, MA (also Dick’s Picks #25)
The reason I have all the details is because I kept a ledger of all the shows that I attended, had a hunch that it might be a good idea to keep track of it.