I go to lots of gigs and often have the frustration of trying to buy tickets before all the touts get them and sell them at massively inflated prices.
I went to the O2 last night and sat right up in the gods as that was the only seats I could get, massively pissed off to see loads of empty seats lower down so either lots of people were struck down with some mysterious illness or the overinflated prices meant the tickets didn't actually sell!!!!! 

Just wanted to rant as it is seriously annoying and about time it was stopped