One of the experiences from my childhood that I remember strongly is during a neighborhood block party, my mom rented a projector and a whole bunch of people watched Star Wars in our basement. I was always fascinated with the planets, and space, and astronauts; I even went to Space Camp when I was 10. It might come as a bit of a surprise that at this point in my life, I vastly prefer Fantasy to Sci-fi.
Really, it’s the Dragons
I know Medieval Fantasy is standard and boring to a lot of people, but if it has swords and magic, I’m still interested. I just like the concept of doing things that don’t really need an explanation. Magic in most settings is internally consistent, but doesn’t work based on any real world principles, and I actually enjoy that. Likewise, fantasy opens up possibilities for things that can’t exist according to physics. Dragons are chief among these, but most of the monster manual qualifies. My initial qualifier, “has swords and magic”, doesn’t lock down medieval settings, as Shadowrun and The Dresden Files also qualify.
Like a Marshmallow
There are exceptions, of course. I’m a big fan of both Star Wars and Mass effect, but neither of those really fits into the realm of hard Sci-Fi. (In fact, both of these settings qualify as “has swords and magic”.) Things like 2001: A Space Odyssey or even Ghost in the Shell tend to lose me after a bit. Star Trek is somewhere in between, because it chooses to disregard odd parts of reality while still feeling like Sci-Fi.