Actor/Actresses

...that turned down roles that brought fame to others. The internet had a list but IMO they left out a few.
The Wizard Of Oz
It was originally supposed to star W C Fields and Shirley Temple. Shirley's mother didn't want her around Fields (a drunk). Then Fields' health didn't permit him to make the movie.

It was Judy Garland's most famous role. The movie was nominated for 5 Oscars including Best Picture. (Lost to Gone With The Wind)

Shirley was given some Oscars but never won Best Actress -and Garland surpassed her as Highest Grossing Child Actress. Oops!

Ballad Of Cat Ballou
They originally wanted Kirk Douglas to play Kid Shelleen but his agent convinced him that he didn't want to portray a drunk. Lee Marvin won Best Actor for that role. IDK if Douglas fired his agent for that or not.

Honorable Mention
They originally wanted Ronald Reagan for several roles that Bogart got
-including Rick in Casa Blanca