Samus because she's so tough and independent. She's just a toal badass! But she still has a heart.

Zelda is elegant, intelligent, gorgeous, and can be strong when she needs to be.

Rosalina is awesome as the guardian of the cosmos. Honestly we don't know much about her at the moment, but she's probably wise and powerful as well.

My top three anyway. Peach is kind of plain, to be honest. She's pretty cool in Smash Bros. though.