What If That One Guy Was In That Thing Instead of That Other Guy

What if Emily Blunt was cast as Black Widow instead of Scarlett Johansson? Russell Crowe as Wolverine instead of Hugh Jackman? Reese Witherspoon as Amy Dunne instead of Rosamund Pike?

It could have been a scheduling conflict. An egoistic actor could have thought the role was beneath them. Or Actor 2 simply lost out on the role to Actor 1. Would the movie/show flop? Would you be interested in the almost-cast actor’s interpretation of an iconic role?

Sound out below. Little-known stories are welcome and encouraged.