The Model Home Mix
Remember those days when you'd make your crush a music mix of your feelings? Well, Marissa did just that for Ryan, who at this point in season one had only really listened to Journey. Which was bizarre, since he had just moved out of his tough hood Chino. It kept him company during lonely nights spent in Kirsten Cohen's now burned-down model home, and featured such songs as Jeff Buckley's cover of "Hallelujah." It was the kind of mix you could light a candle to.
In the third season, just before Marissa's death, Marissa regifts Ryan the mix, complete with its own custom cover. Considering the series released six of their signature O.C. mixes, it's a wonder producers never dropped The Model Home Mix as its own.