Thought that Maroon 5 was pretty good although his singing on Moves Like Jagger was very scratchy..
Didn't care for those rappers. Coming on stage with lots of noise and a fancy car... But the only rappers i like are Snoop Dogg and Eminem (Eminem for the lyrics, Snoop for his style)

And there was a rumor that Mick Jagger was going to be on stage at some point, but well... That didn't happen.