One of my earliest memories is of seeing Forbidden Planet - I was two years old when it was released. Dr. Morbius's invisible mind creature gave me nightmares for weeks. (What were my parents thinking???) It's still one of my favorites.

I do enjoy seeing it every now and then, but I'm always expecting Leslie Nielson to trip over the furniture or something. All of his subsequent deadpan comedy makes it really hard to remind myself he was "serious" once.