Today's open thread, inspired by the superb use of Johnny Cash's "I Hung My Head" during tonight's "Shield" premiere: What's your favorite use of a pre-existing song on a TV drama? I'm not talking about about best theme songs, though there can be exceptions. ("California," for instance, became the theme to "The O.C." because Josh Schwartz loved the way it worked in a scene in the pilot.) I'm talking about "It Was a Very Good Year" accompanying the "Sopranos" season two premiere, or "Full Moon, Empty Heart" playing over a "Homicide" raid (before that show overdid the montage thing), or "Nights in White Satin" over the close of the Sonny Steelgrave arc on "Wiseguy" (which you can see at the tail end of this very long clip, since it's been grievously removed from the DVD because of rights issues), or, obviously, "In the Air Tonight" in the "Miami Vice" pilot. That sort of thing.
So what's your favorite musical moment, and why? YouTube links appreciated if possible but not at all required, especially as I was too lazy to do it myself.