re: Famous roles nearly played by other actors! I’ll start.

Bill Murray was the first choice to play Ted Stryker in Airplane but he wanted too much money.

Vincent Price and Christopher Lee both turned down the role of Dr. Rumeck in Airplane before Leslie Nielson got the part. Price later said it was the worst mistake he ever made in his career.

Pete Rose was originally cast for the role of Roger Murdock in AIrplane then the studio schedule filming for August and September so the part had to be recast.

Carrie Fisher was going to be Miss Scarlett in Clue but she took the role of Miss Star Wars in rehab instead.

Gig Young was the original Waco Kid in Blazing Saddles but his alcoholism got him replaced by Gene WIlder a few days into production.