I saw Slaughterhouse 5 on the A&E channel when I was about 13 or 14. Kinda boring, until the sex scene came up, which somehow managed to make it onto tv completely uncensored. My parents were out in the back yard at the time, so I did the responsible thing: I yelled for my older brother so he could see it too 
Easy Rider when I was about 10. I really, really wanted a dirt bike, and was sure this cool motorcycle movie would convince my dad to let me get one.
That backfired a bit. Oops. Did get a dirt bike a year later
Pretty Maids all in a Row. Angi Dickenson, Rock Hudson with Mom and Dad also when I was pretty young. Squirm.
My parents took me with them to see The Mission when I was little. It made me sob out loud in the theater, to my mother’s chagrin, but what did she expect? The scene that wrecked me – the only scene I remember today – is the scene in which [SPOILERS for a nearly 30-year-old movie ahead!!!] Robert DeNiro is dying and he looks up to see Jeremy Irons carrying the cross through the flames of the burning village. That scene scarred me for life.
Then my parents bought the soundtrack, and I would cry whenever they played it.
Hmm, maybe my parents were sadists…
My parents took me to a drive-in when I was nine years old to see what they mistakenly thought was a movie about animals in Africa. It was The Naked Prey, and in reality it was about native tribes in Africa hunting, killing and torturing some misguided white travelers. The torture scenes were imaginative and horrific, for 1965, and I spent the second half of the movie vomiting in the back of the station wagon because I was so sickened.
Poltergeist, when I was 7, Jaws made me scared of both the toilet and my blue carpeted bedroom (hey, I was little).
I grew up in a neighbourhood where a big group of kids of various ages all played together. It was great, in a lot of ways, but you also ended up seeing a lot of movies you shouldn’t - A Nightmare on Elm Street, Porky’s (all of them), Scanners, Dreamscape, The Birds and a bunch of creepy made for TV movies that I only vaguely remember, all before age 10.
On the bright side, I now have a really wild imagination 
Basically if it wasn’t horror (which I could not handle–after seeing a scene from Dawn of the Dead when I was 5 or 6 gave me nightmares for years), I could see it and pretty much did.
I think I was 11 or 12 when I first saw The Exorcist. As a young Catholic who absolutely believed in God, the Devil and possession, it scared the beejaysus out of me.
Now I’m an atheist and horror movies are by far my favorite genre.
I saw Jaws at 10 and One Flew Over the Cuckoo’s Nest at 11, both with parental permission (in fact, they took me to the theater to see both–Jaws was a drive-in).
Neither freaked me out too badly–I didn’t swim in the ocean so I wasn’t worried about sharks, and I actually loved Cuckoo’s Nest. I was quite the envy of my classroom peers for getting to see an R-rated movie.
I saw the restored version of King Kong when I was a kid; the restored bits included Kong stomping people into goo and tearing Ann Darrow’s clothes off. That was pretty cool.
When I was 17 I went to see an R-rated film while I was underaged (I had a full beard and looked a lot older than I was at the time, so got a ticket easily). Unfortunately, the movie that I chose to see was “Beyond the Valley of the Dolls.” Yes, Roger Ebert’s masterpiece. I left the theater thinking, “If this is adult stuff, I want NOTHING to do with adult stuff.”
Fortunately, adult stuff got better … eventually.
around 1981-1982, my uncle visited our house for several days. Shortly after arrival he bought a piece of brand-new technology: a VCR. We learned that there were stores where you could rent movies on videotape. And so we watched several movies during his visit. I’m guessing he chose the titles. I don’t remember all of them, but two that stuck out were Body Heat and 10. If you’ve ever seen them, then you know they’ve both got heavy sexual content; I probably wouldn’t have minded watching them - WITHOUT three adults in the room (two of whom were my parents). :smack:
Around the same time I also saw Alien on TV. I don’t think they edited out much content - but then they didn’t need to. The movie wasn’t about gore, it was about scaring the living shit out of the viewer. And it worked; I had a hard time sleeping that night.
Cut to a year or two later, at which point my parents had subscribed to some sort of extra channel. Browsing the TV schedule in the newspaper, I discovered that this channel aired “adult programming” late at night. And so one night I stayed up well after my parents had gone to bed (or got up in the middle of the night? Can’t remember), and fired up the TV to discover the world of soft-core porn. It was…eye-opening.
I was obsessed with Titanic when I was a kid. So I watched that movie a lot
I watched The Birds when I was quite little. I had woken up after being put to bed and my mom let me lay down on the sofa and snuggle with her while she was watching it. I was little enough that I know my mom didn’t think I was paying any attention because she was pretty strict about what we watched. I must have been 3 or 4.
It gave me recurring nightmares where I was playing at the beach with my sister and birds would come down and peck at our hair. Then a bird would fly off with a huge chunk of my scalp. These dreams persisted through childhood, my teenage years and into young adulthood, despite having seen the since then and knowing it’s just a movie.
I watched Reservoir Dogs over and over after school around age 12-13. When my mother caught on and watched it herself she taped over it with the Disney Channel. This resulted in much pain as it was my brother’s VHS tape!
I think I might win this one. In my early and mid teens, my father left his adult videos out in the open. In the dining room, out in the open. He took over the dining room table for his work and just left his adult “materials” out.
I must have been around 10 or 11 when I saw Fritz the Cat. The clerks at the video rental store had filed it in the children’s section, probably because it never occurred to them that there was such a thing as a cartoon for adults.
I remember finding the film strange but horribly boring.
If it was on HBO and my parents weren’t home, I’d watch it, especially if the guide said “nudity.”
And then I figured out that if I was patient, the scrambled Playboy channel was sometimes clear enough to see the gist of what was going on. Of course, the audio was often good enough to … um … get me where I needed to be.
My babysitter took me to see The Mountain Men when it came out. It was definitely inappropriate for a 10-year-old! As was The Amityville Horror, which my cousin Jane took me to see around the same time. (Jane was wearing a blue nylon windbreaker that night. I remember it vividly, because I spent the whole movie hiding underneath!) And, lest anyone think that my mom obviously must have had better judgment, she took me to see Midnight Express, when I was about 11. Because nothing could be more kid-friendly than a movie about some guy in a Turkish prison, right?
I kind of give a pass to my cousin Ben, who took me and my brother to see Jaws when we were about six and seven. (It was a long story, which involved him agreeing to babysit us one night, and then making a date the same night, so we all went to the drive in together - how romantic!) When the scary music came on, Ben would shove us kids’ heads down behind the seat so we couldn’t see the gory bits. The Jaws theme makes me vaguely claustrophobic to this day - Ben had a VW Beetle at the time - but I didn’t get scared at that movie! (The scariest bit was the drive home from the movies. My parents were at the same movie, so we had to scoot out as soon as the credits started, drop off the date, and then boogie home in a hurry. And then my brother and I had to run inside and pretend we were sound asleep as soon as we got home - but that, we were used to. Ben never made us go to bed at a reasonable hour, but our part of that bargain was always to pretend-sleep while he cleaned up blanket forts and such as soon as we heard our parents’ vehicle. Best babysitter ever!)
According to my mom it was S.O.B.. I forget if she had seen in the guide that it had nudity in it, or she happened to walk in when Julie Andrews flashed her tits, but she was seriously pissed at my dad for letting me watch it. Next month, no more HBO.
I used to watch all the soft-core, cable porn. Movies like Private Lessons, My Tutor, and such. And when I was in like 6th grade, my aunt took me and my brother to see The Breakfast Club in the theater. She had to lie to my parents, and say that it was rated R “because of one word that they say, like, one time.”