OK, her debt was fleeting, but it startled even Stefani Germanotta, aka Lady Gaga. The self-created pop sensation may have plenty of smarts, but her rapt attention to blowing out her Monster Ball tour overrode her arithmetic. The performer extraordinaire bankrupted herself for the 2009 global extravaganza. "It was funny because I didn't know," she confessed to the Financial Times. "And I remember I called everybody and said, 'Why is everyone saying I have no money? This is ridiculous, I have five No. 1 singles' — and they said, 'Well, you're $3 million in debt.'" She quickly made up for that, thanks to extended tours and an HBO special.