What Makes a Great Horror

Opinions differ, but what makes a great horror? Let me try to formulate this into several segments. Each of them should be considered as my perspectives and ideas surrounding the theme of making an effective attempt at the genre.

And before you object to me, this list is meant mostly for horror movies that could be considered serious, so horror comedies do not apply today.

Originality

Without a doubt, the hardest thing to obtain is originality these days, and horror is no exception. Be it by the setting, an engaging plot, a creature almost unthinkable, weapons, characters, scenes, music and certainly not in the least, sound.

Sound

This is so important for the genre because it goes along with any haunting scenery, any creepy figure, any foreboding moment, any shrieking character, the list goes on. While visuals are the core definition of any movie, sound is arguably more important in horror. 

That doesn't mean that you need cat-scares(which are either false scares or loud scares) to make the lasting appeal all the time. A simple breathing process of a person during a suspenseful scene is enough already to make it effective.
    

Fear of the unknown

This doesn't necessarily have to do with originality, because sometimes, letting the wind gust through a scene with dark objects and a black sky beyond an old window, or hearing strange movements coming from the pipeworks inside the walls might be enough to set us up for something called fear of the unknown.

Sure, you could think that it's just the wind or the pipeworks making the sound, but what if there is someone else present? What if hypothetically, it's your little brother messing around, or it's someone blowing air in the next room?

The greatest horrors don't need visual or audible scares, they just need to mess with your mind and your fragile imagination.

Inspiration

 
And with this, I mostly mean real life situations. Current taboos or large incidents could serve as sources for future inspirations for horror media. If it successfully can drag some of the insanity of real life back into the horror, then that adds another positive aspect for it.

Believable graphics

I think that most people that actually care about this are the same ones that condemn CGI for many awkward and unbelievable moments these days. Good CGI exists, but the majority of them creates huge damage towards the overall experience.

How many times have you heard people say that a certain horror movie was interesting until the "CGI monster" came up? Sure, back in the last century, things weren't necessary great either with costumes and masks, but what I am trying to say here is that I would like to see believable graphics.

It doesn't have to be realistic all the time, just believable so that you could fear it.

High quality

 
Honestly, most horror movies are crap, it's embarrassing. High quality means that the director and it's team has taken care of qualified acting, editing, cinematography, special effects and any other technical effects I might have missed, aside from the elements that usually let the people see a horror in the first place.

Combine all of the above, and you have made a great horror for me. You have also made a great horror if:

-It offends
-It scares
-It's disgusting
-It makes you think that it's creepy insane