Pink Floyd, 1980, the first limited tour for
The Wall (full shows were staged only in London, NYC and Los Angeles.) I saw them at the Sports Arena in L.A.; nothing else quite compares to this show.
Led Zeppelin, 1977,
Presence tour, at the Forum in Los Angeles -- the last time they toured as a band with all four original members. Tour would later be cancelled due to the death of Robert Plant's son. My first really major concert.
King Crimson, 1985,
Three of a Perfect Pair tour, at the Greek Theater in Griffith Park, Los Angeles. Excellent show by an excellent band -- a little mist in the air only added to the atmosphere.
Richard and Linda Thompson, 1982,
Shoot Out the Lights tour, Roxy Theater, Hollywood. Their marriage was in the process of coming apart during this tour, and already-powerful music was amplified by some seriously exposed nerves.
Steeleye Span, 1984, at the Fairport Reunion Festival near Cropredy (UK.) A good band already, they were just really on that night. Singer Maddy Prior was quite pregnant at the time and spent much of the show seated on the edge of the stage dangling her bare feet over the edge, and it was totally cool.
I didn't think I should start a new concert thread so I ask this question here: "How many concerts have you gone to by the same artist?" My top number is three for Morning Musume.
The Grateful Dead easily a half-dozen times; probably about the same for Frank Zappa; Jethro Tull three times; The Who twice.