Stargate is epic and awesome. I loved the spinoff Stargate: Atlantis, based all around the mythology of Atlantis, right down to the shining city at the bottom of the sea. There's a scene in the pilot episode, named "Rising," where the city does just that: it rises to the surface of the ocean. It is the most iconic and powerful scene in all of Stargate. The city of Atlantis represents truth, hope, and knowledge in the midst of a very dark place. I love that kind of imagery...
Plus, the main female lead (for a few seasons, anyway), is a kickass negoiator who, at one point, is blindfolded and handcuffed to a chair in enemy territory with no hope of rescue, and she threatens her way right out of it and scares the pants off her captors (and scores some nukes for the Earth people in the process).
For her badassery in Season 1 alone, Elizabeth Weir will always be my TV hero. Always.
I enjoyed SG1, too. I always wanted to see more of Jonas, or Ayiana, but meh. Guess it wasn't in the cards (especially with Ayiana, being just a guest star and all). The ascension aspect of the Ancients, and the fact that humans are the second evolution of their kind, always struck me as a facinating concept. I mean, yes, the Ancients were here, and they had some badass technology and reigned a really long time. But we're the second evolution of them. We are more evolved, and by extension, have the potential to accomplish even more.
Stargate is the only fandom, other than Chrono, that ever really drew me in.