my top five would be
scarface
casino
blood diamond
the dark knight
transformers

Many great movies mentioned here already so instead of repeating them, I will contribute with some anime movies that haven't been mentioned yet.

I love Movies from Studio Ghibli (My Neighbor Totoro, Spirited Away, Princess Mononoke, Whisper of the Heart etc...) and movies from Studio Madhouse (Paprika, Tokyo Godfathers, Millennium Actress etc...) Ghost In The Shell (the first movie) is also a great one.

Since this thread seems pretty moribund, i will allow myself to offer my personnal list. My favorite movies are those i could watch 1000 times:

"Nosthalghia", "The Sacrifice", "Stalker", "The Mirror" and "Solaris", by russian director Andre? Tarkovsky;
"Persona", "The 7th Seal", "Cries and whispers", "Wild Strawberries", by Ingmar Bergman;
"Memento", by brit Chris Nolan;
"Wings of Desire" and "Paris, Texas" by german Wim Wenders;
"Breathless" and "?loge de l'Amour", by swiss Jean-Luc Goddard;
"The Obscure side of the Heart", by argentinian Elisea Subielo;
"The Night of the Hunter", by brit Charles Laughton;
"Crimes and Misdemeanors", "Manhattan" and "Annie Hall", by american Woody Allan;
"The Gospel According to Matthew" and "Oedipus Rex", by italian Pier Paolo Pasolini;
"Kwaidan", by japanese Masaki Kobayashi;
"Ikiru" and "The Seven Samourais", by japanese Akira Kurosawa;
"A Touch of Evil" and "The Trial", by american Orson Welles;
"The Bicycle Thief" and "Umberto D", by italian Vittorio de Sica;
"Three colors: Blue" and "The Double Life of Veronique", by polish Krzystof Kieslowski;
"The Orders", by canadian Michel Brault;
"The Treasure of the Sierra Madre", "The Asphalt Jungle" and "The Night of the Iguana", by american John Huston;
"The Thin Red Line", by american Terrance Malick;
"Secrets and Lies" and "Naked", by brit Mike Leigh;
"The Raven" and "The Wages of Fear", by french Henri-Georges Clouzot;
"My Uncle Antoine", by canadian Claude Jutras;
"Ulysse's Gaze", by greek Theo Angelopoulos;
"The Great Illusion", by french Jean Renoir;
"Angel Heart", by brit Allan Parker;
"Amen", from french Costa-Gavras;
"Path of Glory", by brit Stanley Kubrick;
"Orpheus", by french Jean Cocteau;
"Four Friends", by american Arthur Penn;
"Death in Venice", by italian Luchino Visconti;
"Modern Times", by brit-american Charles Chaplin;
"Matewan", by american John Sayles;
"Ryan's Daughter", from David Lean;
"Hamlet", by Kenneth Brannagh;
"Amarcord" and "Fellini Satyricon", by Federico Fellini;
"The Woman in the Dunes", by Hiroshi Teshigahara;
"Faust", by Wilhelm Murnau;
"Double Indemnity", by Billy Wilder;
and many many more of course.
I think it is now and for ever well established, for anyone who cares, that i'm not only an old fart, but also a g.. dm.. pretensive asshole. Thank you.

Dracula
School for Scoundrels ( the old one )
the wicker man
fearless vampire killers
sleuth ( the original )
curse of the crimson alter
age of consent ( helen mirren )
pandora and the flying dutchman
scrooge
the scapegoat ( alec Guinness )

Favorite movies
 

;) In no particular order are;
Animal House
Dave
The Godfather I and II
A Man Called Horse
A Few Good Men
Backdraft
Ruthless People
Silverado
High Noon
Harvey with Jimmy Stewart
Kelly's Heroes
MASH
Dirty Dozen
The Russians Are Coming
The Town
Dirty Harry

Anything made by disney :)

Common people the movie with the best cast and best action movieis still "Heat":respect:

and of course my other fav movies are
- Equilibrium
- Bravehart
- The last of the Mochicans
- Any given Sunday
- Lilo and Stich:yes:
- Taxi (French);)
- The girl with the dragon tatoo
- Rounders

Let's see ... ummmm!

Timeline, Crouching Tiger Hidden Dragon, Under a Tuscan Sun, Indiana Jones films, Princess Bride, Guess Who's Coming To Dinner, Sweet Home Alabama, The Italian Job, Somewhere in Time, Pleasantville and Sleepless in Seattle.

Nobody has mentioned Fear and Loathing in Las Vegas! :(

... and The Big Lebowski.

A further favorite is Harley Davidson and the Marlboro Man.