I suppose the best was Frank Zappa and the Mothers at Princeton University in spring of 1973. They had a stereo PA system, probably the first time I’d experienced that, and I had a center seat, maybe 20 rows back from the stage. Even though it was in a gym, the sound was surprisingly good, especially for that time period. It probably helped that I was on acid. Good setlist and they had the principal personnel from Overnite Sensation, including Ricky Lancelotti (singing "Fifty-Fifty") and Jean-Luc Ponty, who didn’t appear in all the concerts of that tour. I saw Zappa a couple other times, in 1974 I think, and wasn’t as pleased.
One runner-up was Brian Wilson at Davies Hall in San Francisco, when they performed "Smile" and lots of other classic Beach Boys songs. They duplicated all those arrangements very well, and the singing was fine, too. I wasn’t really that crazy about "Smile," to be honest--a few great songs, but a lot that didn’t strike me.
Another very good one was the Pat Metheny Group at Berkeley's Greek Theater, in 1977 IIRC. They had just put out the Pat Metheny Group album, and performed lots of that excellently. Metheny and his group were so uniformly excellent that I tended to take them for granted, I guess. But I can't think of another group that could come close to them.
