Battlestar Galactica is a surprisingly smart show. It's got the hardware of sci-fi, but has deeper characters than almost anything else on TV, as well as a fascinating, if dark, sensibility (which is probably understandable when your pilot has the human race nearly wiped out).
I also liked how audaciously they ended last season--after the humans settle on a planet, the show flashforwarded a year. But, after watching the third-season premiere, I'm not sure if this gamble has paid off.
First, we're in stasis, with most of the humans stuck on a planet run by the Cylons while the rest hide in space. Second, we've lost the sense of quest, since the original plot engine of searching for Earth seems to be gone. I'm not saying every episode has to be filled with action, but this is a slow way to start.
Third, and worst of all, is the politics. This used to be one of the best things about the show--how it commented on the world today (as much sf does) as well as humanity in general. In the past, though, this was all part of what helped drive the story forward. Now, with discussion of suicide bombers and the like, it's getting heavy-handed. I still want the political stuff, but not front and center.