98. Solange Knowles
Age (circa 2009): 23
Forget Jamie Lynn Spears and Ashley Simpson—the crown for coolest (and hottest) pop star sibling has to go Beyonce's baby sis. Unlike the robotic drone of her sister, the single mother isn't afraid to admit she has vices: weed and Corona. As soon as she grows her hair back, we're back on it!
Managing to briefly creep out from under her sisters shadow with her decent second album Sol-Angel and the Hadley St. Dreams.