I hope no one takes offense to this....but #10 is #1 for me....I understand if there is a physical handicap, but otherwise, dance around and enjoy yourself! You paid good money to be at that concert, you should enjoy it to the fullest!
1) Taking pictures the entire freaking show
2) Checking e-mail, Facebook and Twitter every couple of minutes
3) Incessantly talking to your friends
4) Yelling out requests
5) Yelling out "Freebird!"
6) Pushing your way to the front
7) Getting so drunk you puke
8) Loudly complaining after the show because the band didn't play your favorite song
9) Filming the entire show on your iPhone
10) Yelling "Sit down!" at people who are standing up