While Alfred Hitchcock was not a great director, he could have been, and his failures are often more fascinating than far greater films. One of his greatest films, however, is The Birds, which I mentioned below.
Here is the original trailer:
Here is a cool, condensed version:
The reason the film works is because it is realistic, save for one key element being off. In fact, many sci fi or fantasy films that work, do so precisely because they don't require superhuman BS to come into play. Think of Dave Bowman in 2001: A Space Odyssey. Think of Colonel Taylor in The Planet Of The Apes. Think of the cast of the original Night Of The Living Dead. Think of the characters in Colossus: The Forbin Project.
The cliche about human civilization being a thin veneer is true, in many ways, and these sorts of films exploit that to the fullest logical extent. Imagine being confronted with killer computers, talking apes, walking dead, or wilding birds. How else, but the way most of these films play out, would people react?
Why Hitchcock failed as a great director is because, unlike Ingmar Bergman, Akira Kurosawa, or Michelangelo Antonioni, he was never able to let go of his rationality- save for films like Psycho, The Birds, and a few others. He lacked Keatsian Negative Capability- the ability to make seemingly irrational leap of faith connections that, in reflection, are not irrational.