New to my Movies You Might Not Know list: "Mistress," a 1992 release starring Robert Wuhl as a down-on-his-luck moviemaker with a good script he wants to direct, if only he can find the money to make it.
To the rescue comes Martin Landau, as a producer who promises more than he can deliver. That leads to three possible investors (Robert De Niro, Danny Aiello and Eli Wallach), each of whom would be happy to bankroll Wuhl's movie, on one condition -- each has a mistress that must be cast in a starring role.
It's not the greatest movie about the sleazy side of Hollywood, but with a cast like that, and the opportunity to watch Landau chase Ernest Borgnine around a parking lot, what's not to like?
See the entire Movies You Might Not Know list here, and feel free to add your suggestions.