I will try to answer this question to as what film gives me my perfect horror fix, and explain why the film appeals to my taste.
1. THE SHINING. This film has everything of which I love, ghosts, isolation, a child character who draws you in through his fear, eerie twin girls and the great Jack Nicholson and Shelley Duvall. This is a film which I can watch over and over and never get bored by it. I think it is good how Jack is influenced by 'Lloyd' the butler and starts to see the ghosts as real, but yet does not see that son 'Andy' is experiencing his own horrors at the 'Overlook Hotel'. The Shining has to be one of the best films ever made.
2. HOSTEL. Now I am not saying that 'Hostel' is one of my favourites, as there are much better films which I could mention. I have put this in my top five simply because it makes you think, 'this could actually be happening somewhere out there'. So many people go missing each year and are never found again! The story of this film is not far from the impossible and that alone is a very scary thought.
3. BLACK CHRISTMAS (1974). I love watching this at Christmas when it is on. It takes me back to childhood being one of the creepiest films I had ever seen. All the sick and twisted phone calls and women going missing, leading up to the police tracing the calls from the same house! What would be more nerve wrecking than realising that the killer is in the same house as you? You are thinking why don't they just get the hell out of there, but that would be to simple and we wouldn't have a film

The scene where he is rocking the girl suffocated by a plastic bag creeps me out the most.
4. ZOMBIE FLESH EATERS. Now yes it is dated but this was the film that gave me nightmares after watching it, when I was about 12, before it was then banned I should add. Zombie was nothing like I had ever seen before, it scared me to death. Even now I have the Italian import DVD of this film and never watch it alone or in the dark

. For this reason, I feel Lucio Fulci (Godfather Of Gore), 'Zombie2' deserves a mention in my list.
5. THE WICKER MAN (1973). Such a brilliant portrayed film. WorRAB to describe, Cult, Festivals, Harvest, Sacrifice, Purity, Belief and Power. It is really scary, the control and influence over people, one person can have. You feel emptiness when 'Edward Woodward' is burnt at the end. You just feel sheer disbelief, like he is a police man, he must escape.
Anyway OP hope you like my top 5 and reasons for choosing them.