1. - Rob Lowe, The West Wing, TV, 1999-2003. When negotiations with Rob Lowe proved difficult, Bradley Whitford was offered the role of Sam Seaborn. Lowe didn’t sign on for the series until the day before the pilot began shooting. And quit in 2003. The series and Whitford in his role of Josh Lyman carried on through 150 outstanding episodes until 2006.