Of all the women on this countdown, no one is burning up with the fever as much as this 19 year-old actress. Gomez threw all caution to the wind like a crazy person last year by going super public--as in award show appearances and PDA-filled Hawaiian vacations--with her younger boy-toy. Of course, this opened her up to a slew of (literally) incomprehensible Twitter threats from 12 year-olds