1. End of GF II.
2. Michael embraces Fredo (and looks at Neri) during Mama's funeral.
3. Murder of Sollozzo and McCluskey (after all, according to FFC, this is the scene that convinced the producers that Al was fit for the role).
4. Michael talking to Carlo: "Barzini is dead. So is Phillip Tattaglia, Moe Greene, Stracci, Cuneo...So don't tell me you're innocent..."
5. Boathouse scene near the end of GF II: "If history has taught us anything, is that you can kill anyone."