See the whole Godfather trilogy. It's good, but you might not want to see all of them at the same time as they are long.
Jaws is cool, but if you're easily freaked out you might not want to, especially if you have any plans on seeing the beach soon. Way back when I was growing up, I'd heard about how my mom saw it in the theaters, and couldn't make herself go in the water at the beaches for the next half decade - decade because she couldn't stop from thinking about great white sharks coming to get her.
And I really don't want to give anything away about silence of the lambs if you haven't seen it.
"If force is the game, the murderer wins over the pickpocket." Ayn Rand
"Justice is the midpoint between being treated unjustly, and treating others unjustly." Aristotle