Die Hard had something of a convoluted history reaching the screen, so bear with me for a minute. The film was based on a book called Nothing Lasts Forever, which itself was a sequel to the novel The Detective. Frank Sinatra played the lead character named Joe Leland in the film version, and he was approached to star in a direct adaptation of Nothing Lasts Forever; he turned it down because he felt he was too old for it. The script was later retooled to be a sequel to Arnies moving classic Commando, with John Matrix fighting a group of mercenaries in a skyscraper. Arnold didnt think it was smart to get involved with sequels at that point in his career, so Commando 2 was scrapped. This is too bad since the script featured a scene where his character tosses the villain into helicopter blades, before quipping He went to pieces. Finally the script was revised to become Die Hard; Arnold turned it down again alongside Richard Gere and Burt Reynolds before Bruce Willis took it on and an all-time action classic was born. But just think of it; there's a parallel universe out there with Frank Sinatra running around in a grubby vest with a machine gun. Can you think of any other examples of sequels that were retooled to become standalone movies? Share your choices in the comments below.