Off the top of my head...
I personally define "perfect" as formally impeccable and emotionally satisfying in every way (story, music,etc):

Citizen Kane
The Godfather
North by Northwest
Grand Illusion
The Good the Bad and the Ugly

Psycho
The Texas Chainsaw Massacre (74)
2001: A Space Odyssey
The French Connection
Treasure of the Sierra Madre
The Godfather
Aguirre, The Wrath of God

Adaptation

Perfect kung fu movie: 7 GRANDMASTERS (1979)

Perfect anime: MY NEIGHBOR TOTORO (1988)

Perfect musical: SINGIN' IN THE RAIN (1952)

Perfect film noir: OUT OF THE PAST (1947)

Perfect western: THE WILD BUNCH (1969)

Perfect sci-fi: PLANET OF THE APES (1968)

Perfect parody: AIRPLANE! (1980)

Perfect cop thriller: DIRTY HARRY (1971)

Perfect heist movie: THE KILLING (1956)

Perfect Hitchcock movie: STRANGERS ON A TRAIN (1951)

Perfect Kubrick movie: DR. STRANGELOVE (1964)

Perfect John Ford movie: THE SEARCHERS (1956)

Perfect Howard Hawks movie: RIO BRAVO (1959)

Perfect John Woo movie: THE KILLER (1989)

Perfect Tarantino movie: KILL BILL VOL. 1 (2003)

Perfect Jason Statham/Megan Fox team-up: still waiting...

For me, Crouching Tiger, Hidden Dragon is a perfect movie. It has everything I want in a movie, done very well.

The Empire Strikes Back
The Shining
Heat

These are probably my most watched movies ever, and all three are perfect in my eyes.

Don't know if it was mentioned, but My Cousin Vinny and A Few Good Men qualify as "The Perfect Movie."

"My Cousin Vinny"? Really? I like the movie but perfect?

I think so. It's funny when it wants to be. Serious in tone when it needs to be. Plus, it has total rewatchability.

Perfect Happy movie: AMELIE
Perfect Sad movie: SCHINDLER'S LIST
Perfect Sci-fi movie: ALIENS, MATRIX, DARK CITY, 2001
Perfect Action movie: THE ROAD WARRIOR, RAIDERS OF THE LOST ARK, TEMPLE OF DOOM
Perfect movie with War in the background movie: UNDERGROUND
Perfect Musical movie: BUGSY MALONE, HAIR
Perfect Pretentious movie: THE FALL
Perfect White Man vs Indians movie: THE NEW WORLD
Perfect Underground Cult movie: THE HOLY MOUNTAIN
Perfect Animated movie: PINNOCHIO, KIKI'S DELIVERY SERVICE, KIRIKOU & THE SORCERESS
Perfect Food/Cooking movie: TAMPOPO
Perfect Horror movie: AMERICAN PSYCHO, BATTLE ROYALE, THE SHINING, JACOB'S LADDER

I've always thought of Goodfellas as the pinnacle of cinema, even though The Godfather I & II usually overshadow it.

Jaws

The original Alien and Aliens are some of my favorite movies to this day.

The first film will be in TCM's 31 Days of Oscar which they began a couple of days ago. There is going to be a whole mess of great films like Lawrence of Arabia airing on that channel in the next month or so all uncut which will make each of my popcorn fueled viewings that much more awesome

I didn't even know they were doing this for February,(very busy) until I heard about it at work as my job does a few marketing campaigns for Turner.

In honor of this assertion, I nominate "Brotherhood of the Wolf":


It's French, for those who want arty and exotic.

It has period costumes and political intrigue, for those who want culture.

It has sword fights and martial arts (but no wire-fu) for action fans.

It has a mysterious beast and a spooky villain for thriller fans.

It has Monica Bellucci.

Win.

This is a perfect movie as well.

Personally, I define a movie as "perfect" if it achieves excellence in its genre and has not substantial flaws. I'd actually have to agree with the guy about My Cousin Vinny. I am struggling to think of any real flaws in the movie and it was a very good comedy.

A Few Good Men, on the other hand, I cannot agree with.

Breaking Away

To each their own. It's a good comedy but it's also at times clunky, hamfisted, and oddly paced.

These things are hard because you always forget something.

But... here's a few off the top of my head.

'Hero' - One of the most perfect movies ever made. Film as pure art.

I second 'Stalker' and would add 'Andre Rublev'.

'Ikiru'

'The Limey'

'Le Cercle Rouge'

'Winter Light'

'Citizen Kane'

'The Twilight Samurai'

'La Grand Illusion'

'Man on the Train'

'Only Angels Have Wings'

'The Searchers'

'Asphalt Jungle'

'Ugetsu

I second 'The Wild Bunch'.

Alien

Not only is this one of my favorite movies of all time but I picked this movie using the following logic: As I was leaving at the end of the flick, I noticed I had a large Coke. I then realized I had never touched it AT ALL during the movie. To me, THAT is a sign of a good movie.

01: My Cousin Vinny
You had the high drama of the arrests of the two youths, the suspense on whether Vinny knew anything past the 3rd grade, the horror of the judge picking on ignorant city slickers, and the joy of the aquittal.

02: Groundhog Day
I think this is a flawless movie. I think this is a flawless movie. I think this is a flawless movie. I think this is a flawless movie. I think this is a flawless movie. I think this is a flawless movie. I think this is a flawless movie. I think this is a flawless movie.

03: The Poseidon Adventure
You wanted to cry when Shelley Winters died. Admit it! Any movie that makes you want to cry over an overweight actress putting on the "I'm Dead" look, well, seems to me like its ---->perfect!

I suppose each person has their own ideas of a perfect movie because it presses all their buttons in the right ways. I think a truly good movie is one that even if you don't particular enjoy it, you'd respect it nonetheless. I lent two freinds Fargo and they called it the stupidest and dullest movie they've ever seen, and I have no qualms about calling them nuts about that opinion.

Jumping into the Raiders convo, it's got some major plotholes:
- How did Indy get into the Nazi sub?
- How did Indy and Marion get away in the end? They were tied to a pole in an island in the middle of the Atlantic occupied by the enemy.
- Indy is a useless element. If he were never there, the Nazis would have dug up the Ark, opened it and gotten killed anyway.

But nonetheless, Raiders is one of the best movies around because you don't even care about these points. Nobody bashes Jaws on the basis that sharks don't actually behave that way, it's just a perfectly made movie. And in that movie world's rules it follows them consistently.



All that being said, anybody who doesn't love Ikiru has no soul.

Although not as loud a fanfair of The Godfather or Goodfellas.

I thought Carlito's Way and Donnie Brasco were perfect.

As for adventure, Back To The Future is just perfect in my eyes.

^^
Ah, beat me to it.

This:



is the quintessentially perfect movie. It's endlessly rewatchable. Everyscene flows perfectly into the next like clockwork.