Ian McKellen in The Lord of the Rings: The Fellowship of the Ring (2001)
Sean Connery was the studio's first option for the role of Gandalf the Grey. He (Connery) declined because he had never read J.R.R. Tolkien's novel and just "didn’t understand the script." If Connery had taken the part he would've earned around $400 million, which is more than any other actor has ever been paid for a single role ever!