Lol! Aww man! Firefly was excellent! Serenity movie was what drew me in. Sucks they only had one season.
I was going to also mention horror as a sister to sci-fi....kind of, but wasn't sure. Yes i agree Supernatural is good. A couple of good scary sci-fi.... The Fourth Kind, and Event Horizon. Hell yeah.
Call me childish, but i also really Stranger things. Reminds me of Super 8.