My favorite horror film bar none and top 5 film overall for me. It is not a perfect film, but there are things about it that are perfect.
One thing that people overlook a lot is the OVERALL score. People refer to the "Halloween theme". That's the "main theme" that most people are familiar with. It actually has about five pieces that are distinctly themed and signify different things.
Here they are, I'll put the main one last -
Judith Myers theme
Laurie's theme
Myers house theme
Stalking theme
Main theme
The genius of all this is that working with a shoe string budget they were able to imply extra meaning to what might otherwise be mundane shots. I was always partial to Laurie's theme in particular as it makes great use of this technique.