1. Taylor Swift
Taylor Swift doesn't go out drinking, she's rarely seen without a pretty dress, and she's best friends with fellow good girl Selena Gomez. That said, her dating life shows there's a little more to her than her ultra-innocent facade. For example, she dated John Mayer! Yes, the country cutie once dated the notorious ladies' man, who's 12 years older. It didn't end well, and her song, "Dear John," is thought by some to be about him.