Eminem

Eminem, Rihanna at Lollapalooza
Eminem surprised Lollapalooza attendees on Friday, Aug. 1, when Rihanna appeared on stage and joined him for three songs: 'Love the Way You Lie,' 'The Monster' and 'Stan.'
50 Cent Will Only Accept Criticism From Eminem
There are a lot of things 50 Cent will do -- including offer you advice, shovel your snow and/or date Chelsea Handler -- but one thing he won't do is accept criticism of his music, unless the person giving it happens to be Eminem.