As part of 
Now this is a serious challenge for me, as she said "favourite"... I've loved horror movies since my earliest memories. I distinctly recall being a little boy and asking one of the Big Kids (2nd graders) how to spell ghost, as I was writing a ghost story...
When she says "Scariest"... how precisely are we to judge this? Does she mean "shit-that-will-make-you-cry" or "really awesome fun scary movie"? This is an important distinction to make... Sadly, I'm still going to be working hard to see if I can manage to narrow it down to 5.
Lady, there are soooooo many good horror movies. All for different reasons. In the meantime though, I'm going to present a moment of film history so mortifying that I just can't in good conscience put it in your list. Children could be watching....
This is -not- my official entry into the contest,
First: A warning.
What you are about to see is so horrifying, that it has been known to cause sterility in lab-rats, and worse yet, induce spontaneous castration in human males. That's right. Castration.
**THAT KIND OF CASTRATION! **
Viewers are strongly cautioned, as the following film clip was once restricted viewing on network television, and due to it's effects, declared flat-out SATANIC by the Southern Baptist Convention (this is not hyperbole, I remember the preacher going on and on about it.)
Prepare Yourself:
... for the most heavily neutered love song in existence. The 70's produced an awful lot of schmaltzy, wishy-washy, limp-wristed wimpy-ass love songs. Songs about sensitivity... heartfelt, candy-coated, singer-songwriter, sugary-death-bomb, gag me with a friggin' spoon!!
But this shit. They pulled out all the stops on this one... Legend has it that the arguably male singer was force-fed estrogen-laced twinkies for 3 days prior it's recording.
FACT! This film was broadcast in East Germany the night before the guards at the Berlin Wall just gave up and went home!
FACT! This clip was playing on a UHF channel at the precise moment that Mike Tyson lost the heavy-weight title to Buster Douglas!
FACT! Justin Beiber!
Behold:
Forgive. FORGIVE!!!!
Further Edit: I have been contacted by certain parties that demand I supply you with the antidote. Apparently, forceably sterilizing half of Steemit is frowned upon. So here goes.
The following video can fully reverse the damage caused by "Friends in this World", and on occasion has caused viewers' voices to drop an octave or so.
Welcome to Day Zero of your new life. You can never be the same...