I think The Sound of Music is a great movie to see once. After that you’re just in too much pain due to cavities.
I’ve got to emphatically agree with JCL1013 that American History X belongs on this list. It is the only movie that I have ever loved and dread seeing again.
The Sixth Sense. Saw it, enjoyed it, but now that I know the whole deal, don’t really care to see it again.
Ditto Unbreakable.
Titanic.
Rose’s loss haunted me for days - there was a lot of it that I took for an analogy of some stuff in my life.