The Departed (2006) – Director Martin Scorsese wanted Al Pacino
Al Pacino was the director’s first choice for the role of Boston mob boss Frank Costello. Pacino passed on the role though, and Scorsese went with his second choice, Jack Nicholson.
Nicholson said that he wasn’t interested initially, but changed his mind after meeting with the director and actor Leonardo DiCaprio, and decided that the villainous role would be a nice change from the string of comedies he had been doing up to that point.