A biopic of Lucky Luciano might still be interesting for the general public as it's pretty much about the history of the New York mob on an epic scale. Also because Luciano will be recognisable since he already has a fairly visible role in the popular show Boardwalk Empire.

A movie about Roy De Meo will also be interesting as it will be comparable to other films about psychopathic killers such as the fictional Hannibal, the real life Zodiac serial killer, or Monster with Charlize Theron. Good thrillers always sell.

And ofcourse a movie that involves famous individuals such as Jimmy Hoffa or John F. Kennedy.

The general public will probably not be interested in the Scarfo era of the Philly mob, or the Colombo wars. However, a movie about a colorful individual such as Joey Gallo could be interesting for ordinary people.