We used to go to concerts often as a teenager. My brother, me and always a big group of friends. After we'd stalk the area looking for them
We got to meet the singer for Tonic, he was really cool. He was on the phone outside his tour bus when we found him (sound a little stalkerish there...) and he motioned for us to hang around til he was done, and he chatted with us and signed our tickets. We went to a Moby/Bush concert (I'm feeling really old here) and we stopped to ask for directions to the bus parking, and while we were getting them Moby walked over and told us right where they were parking so we got to chat with him, then we drove around and parked right in front of Bush's bus. Grabbed a pic of my brother's van in front of that massive bus, then his van wouldn't start and security freaked out because we couldn't move it. We ended up getting to meet all the members of Bush, but his van had to be towed and never ran again lmao. Met Third Eye Blind too, but I'll tell you who had the best security ever... We saw Matchbox 20 in concert five times, and never managed to get to meet them. We kept getting kicked out of all their secure areas. Every single time. *sigh* my favorite band.
Those are the only famous people I've met, at concerts. Never run into anyone in the real world.