To put it mildly, I've got a fairly extensive library. Cookbooks, biographies, self help, and a massive stack of fiction. Granted, a lot of that fiction is your run of the mill trade paperback quality. Books that, like most of what you see on television, will kill time, but aren't likely to teach you much. The Dresden Files and the Camel Club are a lot of fun, but they won't make you a better person.
Good science fiction however, can help you to look at the world in a new way. I'm currently reading Xenocide, by Orson Scott Card, which is the 3rd book in Ender's Saga (on a side note, I'm jumping up and down excited for the upcoming Ender's Game movie). At first glance, Xenocide has most of your geeky sci-fi pseudo non-sense; aliens, artificial intelligence, space travel, and the evil machinations of an out-of-control interstellar congress.
However, none of that is the point.
Good science fiction, like all good literature, isn't really about the story. The Dresden Files, one of my favorite paperback series, is about the story. Xenocide is about faith and free will.
What science fiction does, is replace just a few facts that we take for granted with new ones.
For example, there are countless non-fiction works that examine the difference and relationship between different religions and what they say or imply about the nature of God, creation, and free will.
Imagine a discussion, if you will, about the relative merits of Catholicism, Chinese Taoism, Secular Humanism, and primitive tribal ancestor worship.
It's okay, you don't have to read one. I don't need you falling asleep half way through my blog. Just imagine one. Long. Boring. Dry. Biased. Irreconcilable.
Now imagine that we replace just one basic fact of reality:
We are the only verified sentient life in the universe
We are one of at least three, possibly as many as five, sentient races in the universe
Suddenly, the entire discussion is in a new light. If there was another species, could they be baptized? If that species only existed as an intelligent life form because of an engineered virus, would they have a soul?
If you realize that they would have a soul, or realize they wouldn't, what does that say about us?
If you accept the notion that God, or a god, could choose to make miracles happen in a way that we would see as mundane, how can you be certain of what is or isn't objective reality. How can you be certain of free will?
More importantly, does it really matter?
By tinting the window through which we examine the world, good science fiction lets us ask the same old questions in a new way.
By asking the same old questions in a new way, we might come up with better answers.
Xenocide helps to examine the meaning of creation and free will in a world where creation worked out differently and it's even harder to tell the difference between free will and structured destiny than it is now.
1984 and Fahrenheit 451 help us to understand freedom by showing us a world without it, which most of us have never seen.
Down and Out in the Magic Kingdom can help you to understand the value of work and productivity by showing us a world with no money, no scarcity, and no death.
In short, good science fiction helps us to rethink and re-imagine our world, but giving us a way to step around the obstacles we've built in our own minds.
All that being said, there's another wonderful thing about good science fiction.
Space ships armed with death-rays.