I've been a trekkie for years. Star Trek is my favorite Sci-Fi series. My Dad likes Star Trek (although not as much as I do) and thats how I started to watch it. I like all the series (even Voyager and Enterprise, which don't seem to get a lot of love from fans). DS9 and TNG are tied for my favorite series, followed by VOY, TOS, and ENT. I love the books too.
As for non Star Trek Sci-Fi stuff, I also really like Firefly, Stargate SG-1, and Star Wars (I like the Star Wars expanded universe, like books, more than the movies themselves).
I was looking around for a Star Trek forum, since I'm really the only one I know who likes to talk about Star Trek, and I found this one. It looks cool, and I'm glad I found it.