5 is an impossible task.
I can give you 25 movies I love off the top of my head, and I could probably add another 75 to make it 100. Movies as various as The Godfather, Lawrence of Arabia, One From the Heart, Deliverance, Citizen Kane, This Boy's Life, Repulsion, La Strada, Once Upon a Time in the West, The Seven Year Itch...
Anyhow, here's 25. M is my absolute favorite movie of all time, that I know. The first 15 minutes of that movie are, IMO, the best ever put on film. Shadow of a Doubt and Laura are next. After that, I don't know.
12 Angry Men
The Age of Innocence
Aliens
An American Werewolf in London
The Apartment
Back to the Future
Baisers Volés (Stolen Kisses)
City Lights
Close Encounters of the Third Kind
ET The Extra Terrestrial
The Fearless Vampire Killers
Gone With the Wind
Jaws
Laura
Lolita
M
Ninotchka
Paris Texas
Psycho
Rear Window
Shadow of a Doubt
John Carpenter's The Thing
Titanic
The Shawshank Redemption
The Shining
T