Sean Connery — Said No to Gandalf ($450M)

Peter Jackson offered Connery 15% of the Lord of the Rings trilogy's box office gross to play Gandalf. Connery turned it down saying he "didn't understand the material." The trilogy grossed $2.99 billion — meaning Connery left approximately $450 million on the table. Ian McKellen took the role and became the definitive Gandalf for an entire generation. Connery retired from acting in 2003, citing frustration with the industry. One wonders if passing on half a billion dollars contributed to that frustration.