#3: Caligula

This movie is all the more horrific because all the events which we witness are true.  Gaius Caligula Caesar was well known to the authors of antiquity as the mad emperor of Rome, to quote GWAR, "Whose purges consumed thousands on his blazing altar of syphilis."  We can start off by saying that this movie is a porn.  The very first scene of the movie features Caligula's uncle Tiberius having a great big syphilitic orgy with a bunch of midgets, freaks, and deformities of nature.  Once Caligula takes over, things only get worse.  He appoints his horse as counsel of Rome.  He leads out his legions to an invasion of Briton, but then has them attack a field of papyrus cane instead.  But the worst part is saved for a Roman general named Proculus, and his wife Livia.  Loudly saying, "In the name of the Senate, and the People of Rome, I Caligula Caesar command it", he slaps a lump of lard on the ass of Proculus and FISTS THE SHIT OUT OF HIM, leaving him prostrated and bleeding.  Leaning over the body of his defiled wife, Caligula then goes on to say, "You can see how I have exhausted myself to make your wedding holy."  There is not much else you can say about Caligula, except "Let's see if Proculus can brighten our day!"

#4: El Topo (1970)

This movie, made by Alejandro Jodorowsky, features a black clad, bearded gunslinger named El Topo (which is Spanish for 'The Mole') riding around on a horse with his little naked son in search of the four gunslingers of magic, who live at the 4 corners of the desert.  The movie has very little dialogue and is made up of very haunting, disturbing and surreal images.  What really got me about this movie was the sounds coming out of my speakers.  The high pitched mechanical squealings and the sound of a screaming rodent caused my pet boxer to run out of the other room to check out our speakers.  She was really stressed out.  I would say the movie has an epic feel to it, although the agenda of El Topo remains totally unclear.  There are no words of explanation to suggest why El Topo is riding around with his little naked son killing people, but there are plenty of dead rotting bodies laying all over the desert, which look like they stink.  The end.

#5: August Underground's Mordem

This movie is the ultimate in gore, and only its lack of surrealism and straightforward progression keeps it from being placed higher on the list.  The uploader claimed it to be an actual snuff film, and I had to look it up after I saw it.  The effects are that realistic.  I was nearly convinced.  This is 2 hours of guaranteed wincing, even for those viewers with a stomach strong enough to get past the first 10 minutes.  You'll never forget it.

#7: Guinea Pig II: Flowers of Flesh and Blood (1989)

This movie is the strangest and goriest of a 6 part movie series called "Guinea Pig".  The rest of them are pretty mundane, but this one is really "out there".  It starts off with a guy with blacked out teeth and a samurai helmet kidnapping with the use of chloroform some random Japanese girl.  He ties this girl up to a bed and starts talking about how the highest form of human beauty is really to be found not merely on the skin but on the innards and viscera of the human being.  He refers to this as the making of bright red blossoms and then saws off her arm.  Then he saws off her leg.  Then he saws off her lips.  The whole time, he is making these fucked up speeches about flowers, and at the end of the movie he shows you the remains of past victims who are maggot and worm covered, and just generally really disgusting.  The director of the movie, Kazuhito Kuramoto, was actually investigated by Japanese police for making a snuff film.  He had to prove that all of his effects were faked by recreating them on the spot.  The dialog and explanations are the 2 main factors keeping this film from ranking higher than 7 on this list.

#8: Johnny Got His Gun (1971)

This is probably the most psychologically disturbing movie on this list.  In terms of gore and action, there is not really that much.  The movie is an anti-war film made in 1971, based on the 1938 novel of the same name by anti-war writer and activist Dalton Trumbo.  It is about a World War 1 Soldier named Joe Bonham who is hit by an artillery shell resulting in a total loss of all his limbs, and his face.  Joe manages to survive this ordeal, and is therefore kept alive as a medical curiosity by U.S. Army doctors, who assume wrongfully that the nature of his injuries have caused his brain to die as well.  Unbenownkst to anyone, Joe's mind is alive and well, but with no way to communicate to the outside world, he has no choice but to retreat into a world of memories, where he does not have to deal with things such as the giant rat shown gnawing on his stumps.  This movie was also the inspiration for the Metallica song and video "One", the first track on "Injustice for All."

#9: Trash Humpers (2007)

Trash humpers is a stupid movie.  Probably the stupidest movie that I have ever seen.  Undeniably, though it is very weird.  No one who has seen it can deny that.  If it was even creative in the slightest, I would have placed it higher on this list.  The fact of the matter is that it's just retards humping trash cans for 2 hours, and the worst part is that it won the DOX Award at the Copenhagen International Documentary Festival.  If you've seen 5 minutes of Trash Humpers, you've essentially seen the entire movie.  I sat through the entire 2 hours.  Afterwards I thought to myself, "Well, that is 2 hours of my life that I can never get back."

#10: Eraserhead (1977)

Probably the most well known of all the weirdest directors, David Lynch set the bar high for himself when he made this movie.  It took 5 years to produce and destroyed his marriage in the process.  At the end of the day, it's actually about the strength of a father's love, but the trick to understand that involves actually watching the movie!  Between the horrors of his inudstrial surroundings, his nightmarish relationship, and the screams of his mutant and eraser-shaped-head mutant-child, the saga of Henry Spencer is not likely to make anything but the strongest impression on its viewers.

#11: May (2002)

May Dove Canady is a weird, unpopular kid who has a lazy eye.  The troubled childhood she suffers as a result is the cause of her creating her only friend, a glass encased doll named Suzie.  Her mother tells her "if you can't find a friend, make one."  This advice is taken literally by May, who spends the later part of the movie removing all the "perfect" parts of her friends and then sewing them into an upgraded friend, the Frankenstein-esque Amy.  To bring Amy to life she gouges out her lazy eye and inserts it into her beloved creation, bringing her to life as the credits roll.  I found myself, in spite of it all, to be strangely attracted to May.  Not altogether surprising, hopefully to the composer of this list. 

#12: Jacob's Ladder (1990)

In this film, a Vietnam war veteran named Jacob Singer (played by Tim Robbins) is finding his life become a series of unending nightmares.  As a result of being administered a mind control drug referred to as "Ladder" during his tour in Vietnam he starts having flashbacks of a terrifying and potent nature.  The movie opens with Jacob and his soldier buddies sitting in the Mekong Delta smoking a fat joint.  It is implied that that is how they got the drug.  Anyways, the enemy attacks, the whole troop goes crazy, and they basically start tearing each other to pieces.  Jake takes a bayonet in the guts and the movie flashes to his adult life in NYC.  I tried to watch this film on acid at a friend's house in '98.  A group of us tried to watch it and we got just about to the part with the creepy old lady on the subway before we shut it off.  In any case, Jake gets the job as a postal worker and marries a demonic mexican.  He finds himself being attacked by malevolent and strange creatures who seem to be in some way connected to the government and the drug given to him and his buddies in Vietnam all those years ago.  This movie has a surprise ending which I do not wish to give away, and to describe it further would be to risk that.  What I can say for sure is that I do not recommend watching this movie on acid.  The events of this movie are partially modelled on reality.  The CIA did a series of experiments very similar to this called MKUltra in the 1960s.

#13: Subconscious Cruelty (2000)

This movie sets its own limits and then succeeds in breaking them.  An ambitious project.  The main character is attempting to transform himself a la Dostoyevsky's Crime and Punishment by committing himself to the creation of the most sublimely terrible act of which he can conceive.  He will murder a woman who's just given birth - but not before he kills the baby right in front of the young mother's eyes.  This culminating event actually serves only to introduce us to the realm of the truly surreal. 
There comes a point in these sort of movies where explanation runs dry, where language itself becomes a barrier.  Some things are too strange to be adequately described, like a strong LSD esperience.  The director (Karim Hussain) did an excellent job of spotting that key moment in Subconscious Cruelty. 

#14: Un Chien Andalou (1929)

Produced in 1929 by the father of surrealism, Salvador Dali, Un Chien Andalou (The Andalusian Dog) features a dream-like sequence in which a woman's eye is slit open - juxtaposed with a similarly shaped cloud obscuring the moon, which is moving in the same direction as the knife's through the eye.  This grabbed my attention quite fast, and I found the literal exhibition of the French phrase "ants in the palms" (meaning that someone is itching to kill) to be creative in the most disturbing fashion.  Whether or not the movie actually means anything or even has a plot is a matter of personal opinion. 

#15: When The Wind Blows (1986)

Imagine that the whole world's gone crazy, that science has opened Pandora's box, and that our planet is only a bomb or two away from becoming a desolate wasteland.  If you succeed then you'll find yourself in the setting of this movie.  Two elderly British people are stuck in their home, tucked neatly away in the center of a radioactive fallout zone.  The sight of people who reminded me of my parents, being consumed by radiation from the inside out, and hearing the music of Roger Waters as it's soundtrack was one of the saddest things I've ever seen in my entire life.  This is not a movie I'll be viewing a second time. 

#16: Last House on the Left (1972)

Back in the day, before he'd permanently ruined his reputation as a serious director of horror movies with crap like the movie Scream, Wes Craven directed one of the most brutal and shocking movies of it's (or any other) time.  Mari Collingwood is a young girl who plans to celebrate her 17th birthday attending a concert with her friends.  On her way, she hears on the radio of a recent prison escape involving a violent set of offenders and serial killers.  After the show, they run into them randomly while trying to score some weed.  They are taken out to the woods near Mari's own home, forced to piss in their pants, and shot in the head in one of the most saddening acts of brutality ever put on screen.  The gang ends up at the Collingwood's home, asking for permission to spend the night.  One of them has Mari's peace medal, given to her earlier that day as a birthday present.  Her parents figure out what has taken place based on that and exact a bloody awful revenge.  The mother gnaws off the one guy's johnson.  Jesus...

#17: Salò, or the 120 Days of Sodom (1975)

The Marquis de Sade is an author remembered chiefly for his attempt to create a literal chronologue of every known perversion.  In this movie, director Pier Paolo Pasolini places some of the worst ones on the screen and into cinematic history.  It's the story of four wealthy and corrupt fascist libertines, who spend their post-Mussolini days kidnapping and torturing a total of eighteen different teenage boys and girls.  They proceed to spend the next 120 days subjecting them to the most extreme and yet sublime sadistic urges boiling in their twisted souls.  This film is rated the 65th scariest movie ever made by the Chicago Film Critics Association in 2006, and this in spite of the fact that it's not even typically considered a horror film.  Pier Pasolini, who created it was murdered shortly before its release.  A tragic footnote to a tragic movie.