It turns out that there are a lot of good classic horror films in the “Public Domain”; that is, they are not owned by any party (copywrite expired) and therefore free to the public. Many such horror films can even be found on YouTube. Some of my favorites are below with the YouTube link.
George A Romero’s original “Night of the Living Dead” is the Zombie film that started it all. First, and still considered the best by many Zombie enthusiasts.
Wes Cravin’s Original “Last House on the Left”. This film was remade recently, but the original is not only more psychologically more terrifying, but also far more graphic.
“House on Haunted Hill” with Vincent Price.
HorrortheQueue is a website that has many public domain horror films. Now these are very old films with outdated effects, but don’t let that fool you. These are still grindhouse quality films, complete with adult content and gore.