Wow, those are some great ones!
I guess my own favorite random encounter was at a Counting Crows concert a while back. Even though there was a torrential downpour (one of those big summer thunderstorms) at the time, Adam Duritz stood in the middle of the crowd (next to me
) and watched his warmup band's entire set.
Just nice to see someone who doesn't have an "I'm a big star so no way am I going to get wet watching the people playing with me, and I'm definitely not getting near the folks who bought tickets to see me" attitude...