Atmosphere, Action, or Supernatural???

Out of the three elements I believe atmosphere is the most effective. I believe this because if a book or movie is classified as "scary", it has to have an eerie setting which makes everything that happens in the scene more intense. An example where atmosphere is the most effective element in Frankenstein, is when Robert Walton describes the feeling of the sea, the fog, the eeriness and how he feels about the horrid ice ahead.  Then suddenly this strange figure appeared out of no where.  Without the set up of the scene you wouldn't have the same picture of fear.  You wouldn't relate with his description of these characters without the type of atmosphere you were set up with.