18 of 24:
John Lithgow and Jeff Goldblum were both considered for the role of Doc Brown in 'Back to the Future,' but the role ultimately went to Christopher Lloyd.
Pictured: John Lithgow (left) appears in a scene from Showtime's television series 'Dexter.' Christopher Lloyd (center) appears as Doctor Emmett Brown in 'Back to the Future.' Jeff Goldblum (right) appears in a scene from the film 'The Switch.'
( Photo / Showtime Networks | Universal Pictures | Echo Films)