48 Hrs. - Turned down the role of Jack Cates (played by Nick Nolte). Well, now, it's one of Nolte's iconic roles.
Beverly Hills Cop: Before Murphy and Stallone, Rourke was the original choice to play Axel Foley but went to do The Pope of Greenwich Village instead (which is a fine film but quite an overlooked one).
Top Gun: Was offered some role but turned it down as usual (might be Tom Skerritt's, I guess).
Platoon: Oliver Stone wanted Rourke for Sgt. Barnes (Tom Berenger), but he just turned it down. With all the facial surgeries he had down the road, he could've easily been cast as Sgt. Barnes in a spin-off film.
The Untouchables: Both Rourke and Don Johnson turned down the part of Eliot Ness. I mean, these guys, they just turn down roles in movies like this and go on to star in dumb movies like Harley Davidson & The Marlboro Man. Anyway, The Untouchables helped to make a star out of Costner, though.
Rain Man: Dustin Hoffman called Rourke to offer him Tom Cruise's part, but Rourke simply said, "NO!" Uh oh!
Dead Poets Society: This time Rourke turned down Robin Williams' role 'cause Peter Weir declined to make some changes in the script. Well, Rourke himself is a brilliant (/s) screenwriter (Homeboy), and maybe Weir didn't know that.
Tombstone: Michael Biehn has said that Rourke was the first choice to play Johnny Ringo, but he turned it down. I don't know, man, but turning down roles might be this guy's shtick.
Pulp Fiction: Rourke passed on Butch Coolidge's (Bruce Willis') role so that he could focus on his boxing career. Declining the role of a boxer character that could have helped reinvent your career but deciding to pursue a career you never had. Nice job!
Death Proof: Rourke was intended to play Stuntman Mike, and he'd also have been a perfect fit, imo, just like Kurt Russell is.
Now here's a couple more where he may or may not have turned down the role or was just considered.
Caddyshack: Supposedly, Harold Ramis wanted Rourke for Danny Noonan (Michael O'Keefe), but it's the producers who turned him down here, feeling he couldn't play comedy.
The Big Chill: Lawrence Kasdan offered a role, but Rourke just passed on it.
Highlander: Was originally considered for Connor MacLeod, but seems like he didn't want to be the ONE!
The Silence of the Lambs: Was one of the original choices to play Jack Crawford (Scott Glenn).
Now Rourke is a fascinating actor who was once regarded as the successor to Brando but was blacklisted instead since he had burned a lot of bridges, then one day he was given another shot and got resurrected, and now, seems like once again he's disappeared.
Well, now, of all the actors and actresses, do you think there's somebody else who's turned down as many major roles as Mickey Rourke did? I don't know if anyone else would come close.