I liked BSG, and it was a great show, but as Magisleeper said, it was essentially a soap opera. The drama was pretty intense, and drama's place in Sci-fi (pop culture TV sci fi) historically is usually a bit more tempered.
I grew up watching ST:TNG. I liked watching a Captain who was more of a tactician than a womanizing brawler.
I also watched Babylon 5, and the combination of ST:TNG and Bab5 had a pretty big impact on how I grew to enjoy sci fi as a whole. I think I found Bab5 to be more mind blowing than ST:TNG. Certainly more mind blowing than Stargate(s) and BSG. Perhaps it was just my age and how the series' arcs managed to open my eyes; I can't really say.
Firefly was a really fun show, as well... it had such tremendous promise. Stupid TV execs and their bad taste.
But in the end, I think I'm going to have to vote for Bab5, despite (in all honesty) not likely having seen the full series in consecutive order. It just did so much more to my mind than aaaany other sci fi series I've seen.