Flavorwire has a very intriguing list of “abandoned screenplays” by famous writers like Robert Towne (“Chinatown”), the Coen brothers (“Fargo,” “Inside Llewyn Davis”), Orson Welles (“Citizen Kane”), and Kevin Smith (“Clerks”).  The one I most wish had actually been made is the film written by Roger Ebert for the Sex Pistols, to be directed by Russ Meyer.  I’d say I could only imagine, but I am sure my imagination cannot do justice to what that combination of talent would have produced.  The script is here, so you can imagine for yourself.