Jeffrey Dean Morgan as Denny Duquette
First episode (2006): "Begin the Begin" (Season 2, Episode 13)
Last episode (2009): "Here's to Future Days" (Season 5, Episode 23)
What he's up to now (2020): Jeffrey went on to appear in The Good Wife before landing the role of Negan on The Walking Dead. Also, you can currently catch Jeffrey on Friday Night In With the Morgans with his wife, Hilarie Burton.