The remake of Battlestar Galactica is probably my favorite sci-fi show. I recommend everyone at least give it a shot - it has some of the best single episodes of TV ever made. For some reason, despite the space themes etc, I don't really think of Firefly as sci-fi - it's more of a western to me, just one that happens to be set in the future.
Are we talking the original BSG or the remake? :o) For the remake I can agree with you on season 1, that season was probably the best Sci-Fi television series ever made. But after that I felt it just got worse for each episode (the boxing filler episode in S2 for example) with the entire final season being horrible and the ending being even worse. Of course this is my opinion and noone has to agree with it. You can probably atribute some of the decline in quality to the writers strike with the last two seasons.
The remake. The writer's strike definitely contributed to the show somewhat going off the rails in the latter seasons, but there were still some absolutely stand-out episodes in there.
See my above comment, I tend to agree with some of the "filler" episodes. I am one of the weirdoes that found the final episode to be perfect. I loved it the first and second time I saw it.
I agree with everything you write here. I do think that Battlestar Galactica (BG) suffers at points, but overall it's one of my favorite shows ever. I agree that Firefly is essentially a western set in space. It's badass. I watched BG in less than 2 weeks the first time I saw it. I was hooked. Later, I rewatched the entire series with my wife. It was during this time that I realized how lame the whole Starbuck love triangle stuff was. There are a series of episodes in a row all about relationships which never drive the over arching plot line of "finding earth." -It's frustrating, but worth getting through because the plot starts to pick up again, in a big way thereafter. Such a good show.