What do you think are some of the most chilling moments in a psychological thriller? These are usually movies based on the emotions of characters, with the main plot of the movie more like a setting for the characters.
Some examples are: The Sixth Sense, Signs, The Silence Of The Lambs, Rosemarys Baby, Cape Fear(?), etc.

The Sixth Sense - When the boy walks into the kitchen to find a ghost woman with slit wrists. This is one of those disturbing images that isnt easy to forget.

The Silence of the Lambs - When she is in the basement with Buffalo Bill. Tense shit!