Michael J Fox instead of Eric Stolz in Back to the Future. As originally written, John Lithgow and Edison, his pet monkey, bootlegged porno tapes with Eric Stolz in the back of a video rental place while Lithgow developed a time machine that ran on New Coke. When it worked and Eric Stolz went back to 1955, he had to be driven out to the Nevada Test Site in the back of a refrigerator because a nuclear blast was the only source of energy powerful enough to provide the 1.21 gigawatts available in New Coke. I would say that one improved in the rewrite/recast. Another fun fact: Pris in Blade Runner was supposed to be a bitchy noir brunette while Rachel was supposed to be a blonde ingenue. Ridley Scott saw it the other way after Daryl Hannah had already been cast as Rachel and Sean Young as Pris. Which was deeply unfortunate as Sean Young hated Harrison Ford, which led to the truly rapey chemistry they have on set. I'm one of the biggest Blade Runner fans there is, but imagine it with those two roles reversed... ...even worse for Sean Young, she was supposed to be the interior designer in Wall Street and Daryl Hannah was supposed to be Gordon Gecko's trophy wife. Oliver Stone, however, couldn't see Charlie Sheen's girlfriend as anyone other than a blonde, so Sean Young got boned again. Poor girl. You'd think she'd dye her hair. Or try being less of a bitch, which has been floated as the reason she tended to get bumped out of roles. Another one: As written, Deer Hunter stars a very Christopher Walken-like character as the semi-nerdy kid who goes off to Vietnam and ends up escaping from the Vietcong in a parlay during a game of Russian Roulette... while his gung-ho, all-american tough guy buddy from the steel mill, Robert De Niro, ends up going deep dark black and playing russian roulette for fun and money in the last days of Saigon. Walken is supposed to come back a war hero, fall in love with Meryl Streep and then venture to Saigon in an attempt to rescue Robert DeNiro, not the other way 'round. On a more (as in less) serious note, I've always been a big fan of Joel Grey as Chiun in Remo Williams: And The Duke as Genghis Fucking Khan. Speaking of casting, whenever someone argues it doesn't make a difference I always show them LA Takedown vs. Heat. Same script, both Michael Mann. * In an alternate universe, Bruce Lee was in Kung Fu, not David Carradine.