I havent had any 'bad' experiences with any of the people I met but most interesting ones were...
Bumped into Jacoby Shaddix (Papa Roach) at a bar after a Papa Roach set and he bought me a beer and invited us to his tour bus, also my friends band (False Pretence) ended up opening for them at a stadium gig in Germany after winning a vote on their website and said they were amazing, really down to earth and spent a lot of time with them sharing stories and asking questions about their band.
Also met lead singer of Skindred (Benji Webbe) again after a gig in a nearby bar and he was really cool and had a lot of time people people.
Spoke at length to the former lead singer of Faith No More/Bad Brains (Chuck Mosley) who was going through some really hard times and fighting drug addiction and didnt mind talking openly about it. He was asking if he could stay with people as he didnt have the money to afford hotels even though he was on a sold out tour (he didnt see much of the money), unfortunately he died shortly afterwards of a drug overdose.
Met guys from Black Tide (who were the youngest band to ever play Ozzfest) lead singer was 13 when they were opening for Static-X, Lamb of God, and Ozzy Osbourne and they toured with Avenged Sevenfold. I didnt realise he was so young and said I would buy him a beer for an awesome set and he said 'Thanks man but im not legal'. I laughed and said drinking age was 18 in the UK and not 21 and he replied 'Im 13...'
I ended up buying a shirt of theirs instead.
I later learned they had actually been removed from the main stage at Ozzfest because it was sponsored by Jägermeister and they were underage so were moved to the 2nd stage. My cousin wanted to give them something instead and the only thing he could find in his pocket was a random toy car a younger relative had put there and they laughed and said it was most random thing anyone had given them and they put it on top of the speakers for the rest of the tour.
Just a shame that they changed their style over the years as their first album for a band so young was incredible. They listened to record labels and moved away from what made them sooo good.
Got quite a few (now framed) autographs from bands/singers over the years and I have spoke to quite a few more but those were only in passing.