This is a list with "could-had-been"s. Dodged Bullets. Actors/Actresses that almost played famous roles. Which one of this would had been an awful choice?
http://m.ranker.com/list/the-worst-could-had-been-casting-picks/humbertoibarra,
Arnold Schwarzenegger
Project dropped
Ashton Kutcher
He dropped from the project before it changed
Dougray Scott
Scheduling conflicts with Mision Impossible: II. Role went to Hugh Jackman.
Eric Stoltz
Actually filmed for weeks but was changed for Michael J Fox
John Krasinski
Role went to Chris Evans
Kevin Costner
Turned it down. Role went to Tim Robbins.
O. J. Simpson
Role went to Arnold Schwarzenegger
Robin Williams
Role went to Jack Nicholson
Will Smith As "Clark Kent" in "Superman Returns"
Change in the project but Bryan Singer initially approached him.
Sylvester Stallone As "Clark Kent" in "Superman: the Movie"
Role went to Christopher Reeve