Episode: Season 2, Episode 27
What happens: Long before stepping on the set of The Walking Dead, Jeffrey Dean Morgan played Izzie's sweet and grizzled heart patient, Denny Duquette. After she falls in love with Denny, Izzie cuts his LVAD wire so he could go up the transplant list. After heart surgery, Denny proposes to Izzie. Their romance is short-lived, though, as he dies of a stroke during the hospital prom. His untimely death introduces Grey's viewers to their first taste of a very effective song and death scene combo when Snow Patrol's "Chasing Cars" strums softly in the background.