With Matt Damon, Ben Affleck, and Luciana Barroso
She's a talented actress, an enduring style icon, and owner of the coolest chameleon hair. But perhaps the thing we love the most about Sienna Miller is the fact she always looks like she's enjoying herself! She knows that she's lucky to hang out with some of the world's most handsome men, but her love and affection isn't reserved for her male costars. She also enjoys a giggle with the girls (Cara and Kate, in particular) and shows a lot of love for the directors who've trusted her to take on roles in Oscar-nominated films like Foxcatcher and American Sniper. Time after time, Sienna has been happiest girl in the room, and we adore her for it. Take a look back now at just a few of the many times she's proved she genuinely loves her job!