I assume you're thinking about the HBO movie, "Gotti," with Armand Assante. IMO, this is an entertaining film. The cast--with one exception--is excellent, and carries the film, despite the many liberties it took with the facts of Gotti's career. Anthony Quinn was an inspired choice to play Neil Dellacroce. The others were just as good: Richard Sarafian as Castellano, Marc Angel as Gambino, Vincent Pastore as Ruggiero, and the ever-popular Frank Vincent as DiB.
The exception was Assante. Not that he gave a bad performance, but he was unconvincing as Gotti--he played him with too much energy, drive, intelligence and throughfulness. Assante always plays his roles the same, and his Gotti was no different than his role in "The Mambo Kings."
Tom Sizemore was a far more convincing Gotti in a small role in "Witness to the Mob," an otherwise dismal film about Gravano's life. "Gotti" was a far better film, but Sizemore's performance made "Witness" worth watching (once).