7) John Lithgow
Though previously known for more light-hearted roles in the likes of 3rd Rock from the Sun and Harry and the Hendersons, John Lithgow had something of a career renaissance recently when he gave a terrific performance as the Trinity serial killer on Dexter. Years before that, though, he was asked to play another crazed murderer in Tim Burton’s Batman but turned it down.
In what’s quite funny in hindsight, Lithgow reportedly pulled himself out of the running for the Joker as he did not think the villainous role would suit his particular acting skillset. If he had taken the dive and gone for it though, Lithgow could well have had a very different career where he was known for playing darker roles.