I feel your pain. If you're craving hard-SF TV, I'd recommend Babylon 5. Hulu is streaming the first two seasons and The WB's website is rotating hosting seasons every month (this month they're back to season one). It's not as polished or dark as BSG, but it has all the elements of a great show - finely crafted characters, overarching plotlines, and a real sense of direction. Series creator and showrunner John Michael Straczynski wrote 92 out of B5's 110 episodes, and it's been described as a novel for television.
Of course, SF being what it was in the 90's, the first season is pretty campy. Add on the fact that the actor portraying the commanding officer in the first season is absolutely atrocious and it's a little hard to get into. But I guarantee if you stick it out, about midway through season 2 you'll be absolutely hooked.
I say all of this, assuming of course, that you haven't seen it already. If you have, my bad. If you haven't, definitely check it out.
Also: the prequel TV-movie pilot is terrible, terrible, terrible. Just read a synopsis and start with ep1.