Sasha. She's the quintessential Diva in the way that The Rock is the quintessential "superstar", in my opinion. She's one of the best wrestlers on the roster, male or female, has a great look, and plays her character to perfection on the mic.
You may scoff when I say Sasha is one of the best wrestlers on the roster, but I guarantee, if you were to stick her with somebody like Cesaro the match would be amazing. Ridiculous, but amazing nonetheless. The only person more comfortable than Sasha on the mic in the whole division is Nikki Bella. Paige is getting there as well. She also has a great look. She may not be the prototypical pretty woman but she's in great shape, will appeal to a lot of men, and has a ton of swagger.
Out of all the Diva's, I think Sasha has all the pieces to put together a legendary career.