Melvin and Howard (1980)

  This did not win Best Picture at the Oscars, in case you can't read that tiny print.  It won with the National Society of Film Critics.  Content Warning:  domestic violence

Melvin (Paul Le Mat) is an average guy with maybe more optimism than brains.  The kind of guy who would help an old man (Jason Robards) out in the desert get to Vegas, but also the kind that can't stop himself from spending every dime he has on a boat when his wife (Mary Steenburgen) wins on a game show.  Years later, Melvin sees that the old man he helped was actually Howard Hughes and a mysterious stranger (Charles Napier) leaves him a Last Will & Testament handwritten by Hughes bequeathing Melvin $156 million.  

This is based on a true story.  A handwritten will purportedly by Howard Hughes showed up at the Church of Latter-Day Saints temple in Salt Lake City, Utah, naming Melvin Dummar a beneficiary.  It was eventually ruled a forgery.

This was directed by Jonathan Demme and won Steenburgen a rightly deserved Oscar for Best Supporting Actress.  It's not a bad film, although it really does highlight how ubiquitous domestic violence was in society.  Break out your VPN if you want to watch it, though, because it is not streaming anywhere.