I think I've got it .... the rain in Spain falls mainly on the Plain ...
more seriously, though ..... Rachel Bilson
Rachel Bilson made her screen acting debut in early 2003, appearing in episodes of Buffy the Vampire Slayer, 8 Simple Rules for Dating My Teenage Daughter, and in the short film, Unbroken. Rachel Bilson was subsequently cast in The O.C., which debuted in August of 2003. Her character, Summer Roberts, was intially intended to appear in only a few episodes, but became a series regular after a successful run, as Rachel Bilson's on-screen romance with Seth Cohen (Adam Brody) became a noted aspect of the series.