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After honing her pop chops on Star Search and alongside Christina Aguilera, Ryan Gosling, Keri Russell and Justin Timberlake for on Disney's New Mickey Mouse Club at 11, she and her sexy Catholic schoolgirl uniform exploded on the tween scene with the catchy tune, "...Baby One More Time." The same-named debut sold more than 22 million copies and she followed it with two books co-written with her mom, two more No. 1 albums, 2000's Oops! I Did It Again and 2001's Britney, and an unsuccessful leap to acting (Crossroads). She proved she's "not that innocent" as her style (belly button piercing and nude bedazzled catsuits), performances (dancing with pythons and smooching Madonna) and music ("I'm A Slave 4 U," "Toxic" and "Womanizer) grew increasingly sexier. Her personal life spun outta control. After dating (and losing her virginity to) fellow pop star Justin Timberlake for a couple of years, she randomly made out with then bad boy Colin Farrell, wed childhood friend Jason Alexander in Vegas (and annulled it 55 hours later) in 2004 and started dating backup dancer Kevin Federline, whose girlfriend Shar Jackson was pregnant at the time, the same year. They married and had two sons, Sean Preston and Jayden James, and divorced in less than three years. Things took a bizarre turn when she started partying heavily, publically shaved her head, had a standoff with police, lost custody of her kids and control of her business affairs, checked in and out of rehab and psych wards and gave one of the worst performances in VMA history. The last few years have proved positive with guest stints on How I Met Your Mother and Glee, three more successful discs (Blackout, Circus and Femme Fatale) and a judgeship on The X Factor. She's even happily engaged again to her agent Jason Trawick.