Brewster's Millions
which is probably the most-remade movie ever: "Based on a 1902 book by George Barr McCutcheon, Brewster’s Millions was adapted into an American film in 1914, 1921, 1926, 1945 and, most recently, 1985 [starring the late greats, Richard Pryor and John Candy]. It has also been a Broadway play, as well as a foreign film; two English movies have been made from the premise, and India got into the act with a 1988 version called Maalamaal."