I've been sampling other sci-fi series to take up the slack while waiting for a Serenity sequel. I've seen all the Star Trek: The Next Generation (episodes, and I consider them excellent, expecially the last two or three years. Some very interesting sci-fi themes. My favorite was was where the holodeck Professor Moriarty takes control over the ship; great solution ! I also liked where the ship was caught in (yet another) temporal loop, and the crew was repeating events with slight variations; poor solution, though. The Borg is a great villain.
Star Trek: Voyager is nearly as good. I'm about half way through watching those episodes.
Star Trek: Deep Space Nine was not enjoyable. Too much Ferengi, too little exploration, I guess.
I watched a few episodes of Babylon 5 and could not get into it. Reminded me too much of Deep Space Nine. I suspect I didn't give this show enough of a chance.
I watched several episodes of Farscape. Mixed feelings about this show. The writing was good, but the muppets were preposterous. I noticed that the less human the characters were, the less interesting they were to me. I finally pulled the plug and quit watching.
I'm now watching Battlestar Galactica, the 2003 series, not the old 1979 series. This is very good, so far. The male characters are a bit predictable and play out somewhat unchanging situations from week to week, but the female characters are fun and seem to drive the subplots. I'm not sure if the doctor/Blondie relationship is annoying or amusing, but their presence provides a needed dose of uncertainty to the proceedings in an otherwise fairly rigid framework.
TV outer space sci-fi, on a scale of 10:
10.0 Firefly
8.5 Star Trek: Next Generation
8.0 Star Trek: Voyager
7.5 Battlestar Galactica
7.0 Star Trek (original series)
6.0 Farscape
5.0 Star Trek: DS9
4.0 Babylon 5