Davy Jones (the former Monkee)
Ray Thomas (of the Moody Blues)
That’s pretty freaking cool…on another thread, Duane was on my list of people you had wished you had seen, unfortunately for the musical world, he was killed in 1971, I didn’t see ABB until 1979 when I was 17…
I re-reading this thread, I remembered how our parents dragged us to the Baltimore Symphony Orchestra Saturday Night Pops, as a kid, I actually really liked it, and they would take us to the Lyric to see the off-Broadway shows, so
Leonard Bernstein
Arthur Fiedler
Anthony Quinn
Yul Brynner
Carol Channing
Too many to mention and too depressing, but a few stand out…
Bob Marley, Peter Tosh, B.B. King, Stephane Grapelli
I saw Bob Dylan & The Band in 1974 in Chicago (Before The Flood tour) so:
Richard Manuel
Levon Helm
Rick Danko
I was at Farm Aid in 1990 in Indianapolis so:
Bill Monroe
Carl Perkins
Don Williams
Lou Reed
John Denver
Dick Clark (emcee)
I saw the HORDE Festival in Michigan in 1992 or 1994 so:
Gregg Allman
Butch Trucks
Allen Woody (bassist for Allman Bros. and Gov’t. Mule)
Bobby Sheehan (bassist for Blues Traveler)
You might get the idea I like blues guitar from the following list:
B.B. King
Son Seals
Fenton Robinson
Johnny Winter
Roy Buchanan
Stevie Ray Vaughan
Lonnie Mack
Assorted others:
Carl Wilson
Dennis Wilson
Richard Wright
Chet Atkins
Bobby “Blue” Bland
Jeff Healey
Dan Hicks
Bo Diddley
I can only think of a few:
Chuck Berry
Linda McCartney
Jon Lord (Deep Purple)
Tommy Bolin (different iteration of Deep Purple)
Oh, and I saw Margot Fonteyn dance once.
Ella Fitzgerald (of course, then we need to start debating “win”)
He and Liam Clancy (another, late, great performer) used to do an annual show at the Lakewood (Ohio) Auditorium. Makem used a one-liner that seems appropriate, "Let’s all join hands and we’ll contact the living. " 
I saw them four times. Twice with Duane, once more without him but with Oakley, and once with neither.
Sinatra - even in his old age he put on one hell of a show
Nope. I already name checked him in post #23.
How I could have forgot about Gord Downie I don’t know. I saw the Hip over a dozen times.
Unless there’s some breaking news I haven’t been made aware of, Roy Bittan is still alive. 
My personal list, as far as I can think of, is Carlin, Allen Lanier, Lemmy, Dusty Rhodes, Nikolai Volkoff, Mr. Fuji, and the Ultimate Warrior.
Then you must have also seen Butch Trucks?
You’ve reminded me I left Berry Oakley off my own list. And speaking of the ABB, I’m so envious of you and any others upthread who saw Duane play. I only became aware of him just a couple of months after he’d been killed.
There’s a number of them, but mostly at large tour venues lacking that sense of personal connection to the artist. Which is why Stevie Ray stands out for me. Growing up in Austin, I saw SRV 15-20 times in the 80s, at places like Antone’s and outdoor shows on Auditorium Shores. He poured so much of himself into his music, joy and pain rolling off him with every note. I’d just quit my job to go to grad school and been out late celebrating; my girlfriend (now wife) called the next morning to break the news about the helicopter crash. That was my “day the music died”. I still tear up every time I hear Jimmie singing Six Strings Down.
The other is Townes Van Zandt. Many of his albums were terribly produced, but his songwriting is among the all time best and his live shows were intimate and featured that beautiful, powerful voice.
Biscuit (both Big Boys and Cargo Cult)
D Boone (Minutemen)
Dave Brockie (GWAR)
John Entwistle (Who)
Faye Hunter (Let’s Active)
Jerry Garcia (Grateful Dead)
Grant Hart (Husker Dü)
John Stewart (solo)
Bob Stinson (Replacements)
40% of the original Boston (Bradley Delp and Sib Hashian)
And most tragically of all, House of Freaks, who opened for the Bangles who I attended in the late 1980s and are less well known for their music than they are for the incredibly horrific way one of the members died.
Stevie Ray Vaughan. He jammed with the Fabulous Thunderbirds in Austin in '88.
Ingrid Bergman on stage in 1975. (The Constant Wife)
Gregory Hines on stage in 1982. (Sophisticated Ladies)
Whitney Houston in concert in 1986. (Blaisdell Arena, Honolulu)
Natalie Cole in concert in 1991. (Hollywood Bowl)
George Carlin, and met him after the show.
Ray Charles
Peter Steele/Type O Negative
Tim Wilson (comic/musician)
Robert Goulet (well, didn’t see him perform, but met him)
Bill Hicks
There’ve been a few but the first to come to mind is Ricky Nelson (don’t judge me, the concert tickets were freebies). It was a pretty good performance. Women up near the stage were throwing their underwear at him.