What is your favorite movie of all time ?

Fear and Loathing in Las Vegas (1998)

Shutter Island

Kingdom of Heaven (Director's Cut)
Honorable mentions: Jagten, Moon, Perfume: The Story of a Murderer

Forrest Gump (1994)

Kill Bill volume 1 and 2

WatchMen as a movie.
Akira as an anime, the best, I've read the books too.

Yellowbeard.

pride & prejudice...with keira knightley...im a romantic...i cant help

The Truman Show :)

Lucky#Slevin
50 first Dates
John Carter
Spider-Man (the old ones)

Carpenter's "Dark Star", Proyas's "Spirits of the Air, Gremlins of the Clouds", Jackson's "Dead Alive" .....

P.S. In fact I love a huge number of movies.

Star Wars. All of it.

Just one...so difficult...probably Memento

Forrest Gump (1994)

a korean movie, Brotherhood of War
give it a shot

Historically, I've always answered The Empire Strikes Back.

These are some of my favourties which were not mentioned already here (or I've over read it :) )
Indiana Jones 1+3
Braveheart
Summer Wars
The Big Short
Kick-Ass
Superbad
Full Metal Jacket
Children of Men
Die Hard
Maleficent
Catch me if you can
The Other Guys
Riddick / Pitch Black

Matrix and Highlander

The 5th Element

Pulp Fiction, Spaceballs, Kentucky Fried Movie, The Crow, Attack of the Killer Tomatoes

Excalibur (1981)

One of my favorite scenes from Good Will Hunting :)

Commando