We are huge sci-fi fans in this house. We enjoy watching a variety of genres from fantasy, action, to space fiction. Granted, we enjoy other styles as well, but science fiction is our greatest joy to watch overall. Even on the day my daughter was born, we watched the SciFi channel for hours while we all recovered. Through the years, my children have discovered their own love for watching monsters, spaceships, and magical creatures. They enjoy everything from Mothra Lives, to Doctor Who, to Star Wars (I, and II - the most recent ones) as a small fraction of what they have seen. We aren't big on the traditional "Disney-style" stories around here, so no princesses or cars or the like if we can help it.
As a consequence of seeing what might be considered advanced viewing for their years (although I know many, many parents who proudly declare their kids are rabid fans of Star Wars, etc.), we have spent a fair amount of time explaining the mysterious world of movie make-up and special effects. I think they enjoy picking apart the effects from the reality, and gaining a greater understanding of how much of what they see on TV (be it movies or the news) is actually faked or not quite accurately portrayed.
One of the ways we have helped to show the kids how fake these shows are is to show them. How, you ask. Well, by making our own fake blood and alien goo, showing them using their own bodies, and letting the kids play with it afterwards. It isn't for the faint of heart, as it is quite messy. But it makes for great photos! Oh no, a dismembered arm!! And so forth.
We had such a night recently, and here are some of the action shots. I can't wait until they get older and we can let them film their own movies complete with effects.