It is kind of like all other genres. You rarely find a gem, but like I said... I feel as though making a good horror movie is so much tougher than making a good drama, action, comedy, etc... so it deserves more respect in that regard. Horror movies really showed me how important music and sound design was, for example... if you think of the most iconic horror movies, almost all of them have a distinct sound/music played throughout that you know even if you haven't seen the movie. Best examples are...
Halloween
The Exorcist
The Shining
Friday the 13th
Alien
Saw
Nightmare on Elm Street
Jaws
Jeepers Creepers
Gremlins
Signs
Tv Shows
X-Files
Addams Family
The Munsters
Twilight Zone
I only meant to name like 3 or 4 lol... then I just went off.