Jessica Simpson

Part of the wave of blonde teen pop stars that flooded MTV in the late '90s, Simpson initially distinguished herself with her relatively wholesome image and impressive vocal range. With a minister/manager father and a following on the Christian circuit, she took a while to infiltrate the mainstream, and once she did her moderate success suggested she would soon become a trivia question. All that changed when Simpson and her then husband, former 98 Degrees member Nick Lachey, launched their hit reality series Newlyweds: Nick and Jessica in 2003, which turned the dizzily adorable bride into a household name and eventually led to her big-screen debut in The Dukes of Hazzard in 2005. However that same year, after months of media speculation that their union was on the rocks, Simpson and Lachey went bust. The same thing happened with her next film, 2006's lame comedy Employee of the Month. Perhaps in an attempt to change her ditzy image, she dyed her signature blonde locks dark and began stepping out with smart singer-songwriter John Mayer.