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Rachel flawlessly pairs bright red pants with a sweet floral shirt, both by Erdem.

Cozying up to Karl Lagerfeld and wearing Chanel Couture, Rachel's pretty much living our dream. Sigh.

In another Chanel creation, sans Lagerfeld this time.

Celebrating the one-year anniversary of Phillip Lim's L.A. boutique wearing an awesome metallic short suit by the designer.

We adored this retro-inspired floral Louis Vuitton dress Rachel wore to the 2012 Met Costume Institute Gala.

With her green strapless Bally and poker-straight hair at the 2009 Met Gala, Rachel was definitely channeling her O.C. alter ego, Summer.

In a lovely asymmetrical Lanvin with Alber Elbaz's signature exposed zipper, Bilson proves that some styles just never date.

In lace-overlaid Wunderkind at the 2006 Vanity Fair Oscars party. Ah, trapeze dresses were such a comfortable trend....

In Chanel yet again, this time at the grand reopening of the French label's SoHo boutique in NYC. This look was originally shown with opaque white tights and knee-high white leather boots on the runway, but Rachel's completely made it her own with her simpler styling choices.

Dipping into metallics once more, this time in strapless Lela Rose at the 2005 Emmys.

Stunning and sexy in Roberto Cavalli at the designer's 40th anniversary bash.

Few celebs pull off figure-hugging bandage dresses as well as Rachel, here in Hervé Léger at the 2008 Whitney Art Party.

Alongside Rose Byrne at a party to celebrate Derek Lam's capsule collection for eBay, in a floor-sweeping floral dress from Lam's collab.

Perhaps our favorite Chanel look that Rachel's worn to date (and clearly, that includes dozens), this feathered mint frock is the very definition of a showstopper. Well played, Bilson.