Break out the birthday cake—it's Rachel Bilson's 31st birthday! Since we first met her as Summer on The O.C. and still, as she turns heads at fashion shows and red carpet events alike, the Hart of Dixie star has always wowed us with her incomparable boho-meets-classic style. From floral Erdem to a Chloe LWD, click through to see all of Rachel Bilson's best looks! And catch Bilson on Hart of Dixie when it returns to The CW on October 2nd.