When Jay Z and R. Kelly teamed up for their chart-topping collaborative album, Best of Both Worlds, in 2002, neither knew it would be at the expense of their friendship. Kellz's legal issues interfered with the duo's touring schedule, so they tried again on Unfinished Business in 2004. Kelly, however, dropped out of the tour unexpectedly during a stop in New York, where the singer claimed someone was threatening his life. Jay told the audience that night, "I don't need that n***a."
(R Kelly: Photo: Jakubaszek/Getty Images, Jay Z Photo: Nick Elgar/ImageDirect)