I've only been to a few
Eric Clapton - best performance I've been to what more can I say

Guns N Roses - went to see them at the o2 in dublin, was my first time seeing them, even with the whole bottle thing they were awesome and axl sang even better when they came back out
Oxygen 2010 - left early because of the rain but some of the acts I saw were really good, The Coronas, The Black Keys, Two Door Cinema Club, Biffy Clyro, Florence and the Machine, Kasabian, their singer was high as fuck so that was kinda funny and even though I can't stand his music Dizzie Rascal put on a good show but nothing came close to Muse it's the best show I've seen live only guns come close to it.
S Club 7 - savage