Stargate SG-1 is a science fiction show. We know that because it's on the Sci-Fi channel. (Ha Ha)
Srsly, unlike a lot of other things on Sci-Fi, Stargate is true science fiction. It may be geared to deliver action/adventure, but the "speculative fiction" elements are more than window dressing. They are vital to the show's essence, and that's what puts Stargate squarely within the SF genre.
The label "SF" covers a lot of ground, though. What kind of science fiction is Stargate?
I see a strong tinge of space opera, what with the Good Guys and Bad Guys duking it out to decide the Ultimate Fate of the Galaxy, and the cosmic-canvas themes involving the Ancients* and other Elder Races. There are shades of military SF, too, since the protagonists are soldiers (or scientists who have joined the war effort). But, overall, I'd say Stargate falls under the general heading of "soft" SF. It does use concepts from the hard sciences -- such as the Stargate wormhole itself -- but the speculative/imaginative core of the series lies in the areas of psychology and sociology; philosophy and morals; mythology and religion. The Gateverse really lends itself to exploring those aspects of the human experience, not only because it contains a myriad of human worlds derived from different cultural roots, and involves aliens pretending to be gods, but because it provides characters who are complex, flawed, and recognizably human -- even while also being the sort of larger-than-life heroes you'd expect to find in an SF adventure.
Another defining characteristic of Stargate is the humor, especially the self-referential variety (yes, we're inside an SF adventure show, and isn't it fun?). And there's a bit of romance here and there. The fictional genre varies somewhat from one episode to another.
So, Stargate the TV show is SF action/adventure, with a generous dollop of humor and a pinch of romance. But what about Stargate fan fiction? Is it mostly the same genre as the show, or mostly not?
A lot of the fan fiction I read has a heavy romance element, which is hardly surprising since I'm into ship. But some ship stories are still basically the same genre as the show, just with more emphasis on the romance. That's true of my own fan fiction. However, many ship stories seem to be straight romance, with no "speculative fiction" aspect at all. The SF elements are in the story only because they're an established part of the Stargate universe. Sometimes even that is missing, because the story is set on Earth, and deals with the characters in an ordinary "real world" setting.
I've wondered what that says about why fans are drawn to Stargate. Are a lot of fans into the show only because they love the characters, and get a kick out of putting them into romantic fantasies? Are the thinky SF elements incidental to them?
My impression is that most Stargate fan fiction isn't science fiction, but I'm not the best person to judge. The truth is, I've only dipped my toes in the fan fic ocean. Most of my reading time is still devoted to regular books, and I've read hardly any gen fan fiction at all.
I'd be interested to hear from some of you who know Stargate fan fiction better than I do. What do you think about this?
* One of my pet peeves is the name "Ancients" for the race that built the Stargates. I mean: "Ancient ruins." And it's not as if it takes genius to do better. What was wrong with "Gatebuilders?"