Kevin Federline

If it weren't for Britney Spears, the world would never have heard of Federline, an alternately sleazy/silly backup dancer turned rapper who came to infamy by marrying Spears in 2004. After the couple split in 2006 and Spears went off the deep end, however, the public almost started to sympathize with this pop-culture punch line/tabloid punching bag. After dancing for the likes of Pink and Spears' ex Justin Timberlake, Federline met the pop princess and immediately began courting her, despite the fact that his long-time girlfriend, actress Shar Jackson, was pregnant with their second child. After marrying in 2004, Federline (dubbed K-Fed by the media) and Spears were omnipresent: magazines, parties, even TV with their headache-inducing reality show Britney and Kevin: Chaotic. Spears gave birth to their first son, Sean Preston, in September 2005 and their second child, Jayden James, a year later. But the high-profile parents seemed to be in trouble. Tabloids insisted their union was on the rocks and a series of mothering mishaps including Spears driving with Sean Preston in her lap and, in another incident, almost dropping him highlighted the fact that she was usually flying solo. In October 2006, Federline released his debut album, Playing with Fire, which took a critical and commercial drubbing; a few weeks later, Spears' fans breathed a collective sigh of premature relief when she filed for divorce. But instead of getting her life and career together, Spears went on a partying rampage that culminated in a shaved head and multiple short-lived rehab stints. Although Federline's request for sole custody of the kids initially seemed like a gold-digging tactic, Spears' increasingly bizarre behavior made him look like the fitter parent. He also improved his image by showing he didn't take himself too seriously when he appeared in a Nationwide Mutual Insurance Company Super Bowl ad in which he went from the high life to a has-been in 30 seconds.