Played in the original by: Mia Cottet and Kristin Bauer van Straten
Our choices: Amber Heard and Blake Lively
There's not much distinguishing Cheryl and Kelly in the movie: They're both pretty, blond members of The A Group who hang on Christy's every word. But that doesn't mean they don't deserve A-list talent playing them. (There are no small parts, just small actors.) So we'd give the roles to Amber and Blake because, hey, they're nice to look at.