Live8
There was an excellent band from Senegal called Daara J doing African Hip Hop that got the crowd bouncing and joining in, probably more so than in London. The BBC have a page on the band as well.
Wrasse Records always seem to have a great list of artists on its books.
Funniest moment was watching Snoop Dogg shouting out "Make some mother f*cking noise!" then the camera pans to a 6 year old girl on her dads shoulders waving her hands up in the air.