Lauren Santo Domingo vs. Emma Stone in Giambattista Valli: I have to go with Emma on this look. She wore the ensemble first and just made it look effortlessly "cute". Plus the hair/makeup and nude heels works better with the overall look. 

Alexa Chung vs. Jessica Chastain in Pucci: This is a close one. On one hand Alexa Chung looks casual and stylish. And on the other Jessica looks more dressy and chic. But in my biased opinion I have to go with Alexa!

Lucy Liu vs. Amber Heard in Phillip Lim: I think this one may be a tie because the dress looks great on both ladies. I like Lucy Liu's Charlotte Olympia shoes and purple handbag but not with this dress! I do like how Amber kept it simple with the black shoes & clutch, but I prefer the dress on Lucy (just lose the colorful accessories!)