I got into BSG late, somewhere around the start of 2.5 or 3. Watched them all from the beginning, I was impressed. Although I think season 2.5-end of 3 or beginning of 4 was kind of weak.
The section I think you're referencing, revolved around the humans starting a colony on a planet they called, "New Caprica", which was then subjected to a Cylon occupation. I've heard that particular section of the story called, "the most depressing show on television". I took it as part of the story that needed telling. It was hard to take though, no joy as it were. But, occupations in wartime are most definitely based in fact. That said, I've watched every PBS documentary on the holocaust and Auschwitz I've known about. Those weren't your basic, "NBC Comedy Thursday" fare either.
The beauty of the BSG saga, is that it was allowed to complete, and it coupled into back into the human experience. The most difficult part of creating a successful Sci-Fi show, is creating a mythology that compliments our hopes, psyches, beliefs, and value systems. This show borrowed from, and melded with, the beliefs and values already present in all of us, in a comprehensive way, that prior to BSG was never done.
After watching the fifth season of Andromeda deteriorate into incoherence fueled by Kevin Sorbo's ego, by comparison, and even in its own right, BSG went out in a blaze of glory.
True Blood has a similar ambience to one of Quentin Tarentino's "Grindhouse" movies, at least the teaser episode that aired on network TV did. But with no cable, no joy on that one for me. I keep meaning to open a Net Flicks account, to catch up on some of the cable series, albeit an season late. Stargate Atlantis Season 5 comes to mind as a must see also.