Saw Pat Green at Mile Zero Fest in Key West a few years back and then ran into him at a little bar near our Airbnb after the show. He was ordering a margarita and insisted on buying for our entire group. After all of the shit I've heard about him, I was fully expecting the show to suck, but he was great and we were all pleasantly surprised. Then, to meet him afterwards and for him to be totally cool was also a pleasant surprise. He was in a great mood, when we resisted having him pay for our drinks he said "shit man, if you knew how much they pay me for this you'd take the free drink. It's ridiculous!" Got a big laugh from everyone. He was very laid back, chatting with everyone. I became a fan after not really having liked him that much previously.
Saw Lance Armstrong at the Marfa "Railroad Revival Tour" stop featuring Mumford & Sons, Edward Sharp & the Magnetic Zeros and Old Crow. Still probably the best concert experience of my life. Lance was hanging at the sound booth, but didn't talk to him.
Saw Lars Ulrich of Metallica at the Radiohead show at ACL Fest in 2016. He was hanging in the VIP area by the sound booth with some hottie and we were right in front of that on the other side of the rail from him. We said hi and my buddy and his wife got a pic with him, but that was it.