You're probably talking about "It".

The movies that realy scared me growind up were Terminator 2, The Lawnmower Man (especially at the end), The Village (M Night Shamalayahan), the two first Indiana Jones (especially Temple of Doom), and I guess the Blair Witch Project.

After that I stopped getting scared.

You guys got off easy I grew up with Asian horror movies T_T

JAWS! When it came out, I was even afraid of swimming pools.

There are some places that set up movie screens where you can sit in a pool and watch Jaws. I think that sounds super fun/terrifying.

Cause you just know, someone is going to bump into you at the most suspenseful time.

Terminator 2 scared you??? O.O

I was 8 when I saw this movie, it became instantly one of my favourite movies ever (still is). I and my cousins played it all the time I always the Arnie or the evil Terminator. I made my father to buy Terminator bed clothes because I saw them in a catalog. 

I think most of the scares from horror movies have their impact when one is younger, less desensitized and is more likely to believe in the viability of the various scenarios often seen in the horror genre.

After that age, it does become much harder to genuinely feel fear from what is largely a predictable genre with the same cheap scare tactics used to the point where they are the equivalent of comedic chestnuts/clichés.

But when I was I think about 3 years old the 1977 film "Orca" legitimately scared me and in retrospect, that is not a film any 3 year old should have any business watching. Parenting 101.

The original Jaws also scared me as a very young child.

And the original Nightmare on Elm Street stayed in my head for quite a bit when I was in my tweens.

As much as I love a good horror film, most of the "scary" scenes elicit more groans than gasps these days and it takes some pretty clever writing, not cheap clichéd screen tricks to make me smile when watching a horror film for the first time. Smile = good when I'm watching. It doesn't mean scared, but it does mean entertained or at least surprised, which is good enough for me.

I wouldn't say anything scares me as an adult, but the following films are all perfectly unsettling if you invest in them (mainly Western films although I think many Asian horror films are the best - The Ring, Grudge, etc):

The Shinning
Texas Chainsaw Massacre (original)
Manhunter (Brian Cox Lecter - or Lektor - for me plus a better sense of mad horror than Silence I think)
The Haunting (0riginal - an oldie but still best evocation of sense of spirits ever)
The Exorcist
Alien

Nothing. I wish I was kidding, I think I'm desensitized to horror. The worst I got was feelings of disgust but never really frightened or unnerved. Then again I'm watching a new horror flick every 2nd night or so it's probably become habit now.

Though since some of you are so easily scared I recommend Shutter (2004) the original Thai one. It's sort of like Ju-On but potentially scary. Depends on the person I suppose.

Have you seen 'The Cube' or the original 'The Thing?'

And there is a French Horror film where there are 4 guys in prison trying to escape.  (Can anyone remember what it is called?)

Well in retrospect is not a scary film at all but as an kid it was the reason I was terrified of clowns;..Also the first American movie I saw...Since then it took a long time before my parents let me see another one

The Cube trilogy is one of my favourite Horror movie "series" of all time (Even though Cube 2: Hypercube was more sci-fi lame than scary). 

I saw the original at Fantasporto (which is a horror movie festival in the city of Porto - Portugal) back in 2000 and became an immediate fan. Thankfully, The Cube Zero was as good (if not better) than the first one.