Episode: "Chuck Versus the Sandworm"
Air Date: 10/29/07

Just about every episode of Chuck features Yvonne Strahovski in a hot costume or otherwise graciously revealing clothing, but for the series' first Halloween episode she paid tribute to Chuck's geekiness with the Princess Leia slave outfit, a classic go-to for women who want to be referentially nerdy and look stunning at the same time. At this point in the series, Chuck and Sarah's relationship was still a fake one for cover purposes despite his actual feelings for her. Moments like this definitely added to the pressure.