this world would be awesome if there were actually 117 horror movies better than Psycho (1960)
I haven't watched much horror but I can name a few films that one may classify as horror that I liked more out of my head right now:

- Persona (1966)
- Alien (1979)
- Shutter Island (2010) (yes! )
- The Fly (1986)
- Videodrome (1983)
- PMMM parts 1 & 2 (well, it's classified as horror in wikipedia though I would call it a tragedy/thriller/fantasy/science fiction and it's animated)
- Eraserhead (1979)

I imagine that someone who likes horror very much will be able to show a very long list of better horror films than Psycho. You should also know that hollywood only produced 20% of all films in existence, so there are several great horror films made outside of the US for every great US horror film.