Harrison Ford as Bill
Cracked had an article about if Harrison Ford was cast in the film instead of Tom Cruise, and the writer makes a good point:
Kubrick made the unfortunate decision to stunt-cast Tom Cruise and his wife Nicole Kidman, well before anyone realized what a horrific idea that was. Of course, the couple weren't so much "vanilla" as they were way more uncomfortable around one another than any married couple should be. According to R Lee Ermey, Kubrick regarded the film as a "piece of shit," and claimed that Cruise and Kidman "had their way with [him]."
The film wasn't as bad a Kubrick feared, but his concerns do raise the question: Why not go after the guy you're patterning the character after?
You get a better actor who maybe, invigorated after working with Kubrick, doesn't turn into a perpetually stoned stroke victim. Ford probably then ends up taking the lead role in Traffic instead of abandoning it to Michael Douglas, and wins himself an Oscar for it. Any possible future where we're spared Hollywood Homicide is a future worth pursuing.
And Eyes Wide Shut? Han Solo fumbles with his junk at an orgy. Indiana Jones awkwardly hits on a 15-year-old Lelee Sobieski. Jack Ryan starts licking his wife while checking himself out in a mirror. It would have been Harrison Ford as you've never wanted to see him. The most squirmingly uncomfortable thing Kubrick ever put on film -- just like he wanted, but for all the right reasons.
https://www.cracked.com/article_18455_5-movies-that-were-one-flaw-away-from-being-classics.html