Cult Science Fiction Films

So, what is a Cult science fiction film? Aren't all Sci-Fi films essentially Cult? Well, the author asks this question in his intro to the book and comes up with a few answers: there is something special about a sci-fi film to make it Cult. One special facet may be an actor, whether appearing very early or very late in his career in such a film (one example is The Medusa Touch/'78 - in the book - but is this film really cult because Richard Burton appeared in it?). Planet of the Vampires (1965) with Barry Sullivan was also singled out. Another special reason may have to do with very loyal (fanatical?) fans of a certain film. Some Sci-Fi films are so bad (Robot Monster) that one just has to love them, "like homely puppies." In any case, there are 75 films singled out for cult status in this book; here is most of the list:
Since there aren't very many films in the book, this enables the author to devote an average of 3-4 pages of commentary & stills for each film. Each entry begins with the standard director/actors info, as well as studio.

With such a short list, however, it's inevitable that questions will arise as to the reasons for many exclusions. A lot of this has to do with space reasons, of course: the author admits he wanted to include Missile to the Moon, Night of the Blood Beast, Not of This Earth, Re-Animator, Slime People and First Spaceship on Venus and wasn't able to. He also purposely excluded big productions like Blade Runner, Alien, and Predator, which have been written about ad nauseum. But why include Piranha (1978) rather than any of the other innumerable eco-terror films of the seventies? That, Sci-Fi fans, is for you to ponder...