The picture is the question.

[Svengoolie 3]

For me,  "Them!" When the giant ant reared up behind the woman... 

[Pacman000]

That I can remember:

Aladdin. Got the video tape for my birthday when I was too young, before starting grade school, & it scared me so badly I didn't watch it again for years. We considered getting rid of it a few years later, but I watched it again & enjoyed it.

Runners up would be The Little Shop of Horrors (1986). Saw it around 1st or 2nd grade & it made me afraid of plants for months.

Chances are The Wizard of Oz scared me too.

[FatFreddysCat]

Pretty sure it was the original Amityville Horror. I was about 9 years old and it scared the ever lovin' poop outta me.

[Allhallowsday]

The earliest would be ISADORA DUNCAN, THE BIGGEST DANCER IN THE WORLD (1965) 

NIGHT OF THE LIVING DEAD (1968) 

TEXAS CHAINSAW MASSACRE (1974) 

[Alex]

When I was about 6 or 7 'The Boogey Man' gave me a good fright.

[LilCerberus]

The outer limits
It crawled out of the woodwork

[indianasmith]

THE LEGEND OF BOGGY CREEK.
My brother took me to see it when I was around 7 years old.
The bathroom scene freaked me out so badly I didn't poop for a week!

[Svengoolie 3]

THE LEGEND OF BOGGY CREEK.
My brother took me to see it when I was around 7 years old.
The bathroom scene freaked me out so badly I didn't poop for a week!

(Virtuously resists urge to make "full of xxxx" joke...)

[justme2013]

Sven I think we're on one of the same facebook groups lol
and I'll give the same answer here that I gave there, Watchers in the Woods

[BoyScoutKevin]

Easy.

The Fly (1958) The original with Vincent Price and Al "David" Hedison as the title character.

[Flangepart]

The Blob (original) Scared me right out of the movie theater.

[RCMerchant]

the PIT AND THE PENDULUM  with Vincent Price and Barbara Steele.