I have several.
-Meeting Ringo. I thanked him for all the marvelous music and he thanked ME for being a lifelong fan. On bad days, I remind myself that I met a Beatle.
-I had an opportunity to golf with Dicky Betts and Les Dudek about 20 years ago. Shortly after, I was a guest of Dicky in a SW Florida recording studio with the Allman's as they were fleshing through the songs that became "Where it all Began". I got to meet Tom Dowd, also a treat. Funny white dust all over the bathroom, though.
During my fellowship, I took care of the current singer in Fleetwood mac. I was expecting to meet a real bitch. She was the sweetest most genuine person and hung around the office chatting with me for about 30 mins talking about Lindsey and their prior band. I was so star struck, I apologetically asked for her autograph, which I still have on a Rx pad
-Sitting in the auditorium of a local community college on the bleachers watching a warm up band Skyhook on Kiss first tour. Crappy little auditorium and stage. Lots of facial paint in the audience. A guy sat right behind me and a little to my right with vampire facial paint and a top hat. After the warm up band finished, I saw him take the stage-it was Gene Simmons. He had switched to his vampire attire at that point.