Enemy of the State (1998)
Who was considered for Enemy of the State?

Tom Cruise
Tom Cruise turned down the role of Robert Clayton because he was still working on Eyes Wide Shut.
Actor who got the part: Will Smith

Gene Hackman
Gene Hackman turned down the role several times before finally accepting…
Actor who got the part: Gene Hackman

I, Robot (2004)
Who was considered for I, Robot?

Denzel Washington
Said in an interview that he was approached to play the lead.
Actor who got the part: Will Smith

Jersey Girl (2004)
Who was considered for Jersey Girl?

Bruce Willis
Bruce was offered the chanced to play himself. He was sent script but didn’t get back to director about it.
Actor who got the part: Will Smith

Renee Zellweger
According to DVD commentary, producers were considering Renee and numerous actors for the role of Gertrude.
Actor who got the part: Jennifer Lopez

I Am Legend (2007)
Who was considered for I Am Legend?

Jennifer Connelly
In the mid nineties Jennifer Connelly was to play Schwarzenegger’s wife in director Ridley Scott’s adaptation of the Richard Matheson novel. They were the only two actors to be cast before the project was abandoned.
Actor who got the part: TBA

Tom Cruise
According to the Toledo Blade, Tom Cruise turn down the lead role.
Actor who got the part: Will Smith

Arnold Schwarzenegger
In the mid nineties Arnold Schwarzenegger was set to star in director Ridley Scott’s adaptation of the Richard Matheson novel. No villain was ever cast for the film.
Actor who got the part: Will Smith

Ridley Scott
In the mid nineties Ridley Scott was set to direct an adaptation of the classic Richard Matheson novel. However the project eventually fell through. Recently it has been announced that Francie Lawrence will direct the movie after impressing studio execs with his work on Constantine.
Actor who got the part: Francis Lawrence

The Legend of Bagger Vance (2000)
Who was considered for The Legend of Bagger Vance?

Morgan Freeman
Robert Redford originally wanted Freeman to play Bagger Vance, but ultimately decided to cast the movie with younger actors.
Actor who got the part: Will Smith

Brad Pitt
Pitt turned down the role of Junuh.
Actor who got the part: Matt Damon

Robert Redford
Robert Redford was going to play Junuh, before deciding to cast a younger star in the role.
Actor who got the part: Matt Damon

Men in Black (1997)
Who was considered for Men in Black?

Clint Eastwood
Clint Eastwood turned down the role of K.
Actor who got the part: Tommy Lee Jones

Chris O’Donnell
Chris O’Donnell was considered for the role of J.
Actor who got the part: Will Smith

David Schwimmer
Schwimmer turned down the Will Smith role.
Actor who got the part: Will Smith

Will Smith
Will Smith Originally turned down his role in Men in Black, however his wife eventually talked him into reconsidering.
Actor who got the part: Will Smith

John Turturro
John turturro was offered the role of Edgar but turned it down due to other commitments.
Actor who got the part: Vincent D’Onofrio

Source: Notstarring.com