Johnny Dangerously. 😛
My Cousin Vinny, actually. Good way to move on to Goodfellas.
Also, the original Godfather is intelligent, well written and has excellent acting and only scattered scenes of strong violence spread throughout the 3 hours of the film.
Plus, it's a draw for showcasing young Robert Duvall, young James Caan, young Diane Keaton, and young Al Pacino in his first starring role. That should help generate some interest.