Last night I finished watching the released episodes of Battlestar Galactica (through the end of season 4 part 1). Don't worry, there are no spoilers here—and a lot of crazy stuff happens in the last couple episodes.
I think that Battlestar Galactica has fallen prey to the same thing that happened to The X-Files: it's very impractical to watch an episode out of order anymore. At the beginning, The X-Files was all about the absolutely self-contained episodes. Each episode presented a paranormal mystery, and by the end, the case would be closed. Not necessary solved or fully understood, but closed. By the end of the series, many of the episodes were hardly about the paranormal at all, simply resolving the complicated mythos that the show presented. I still liked the show, but it was very different than what I signed on for.
Battlestar Galactica is getting to be the same way. It's not that I don't like the show—in fact, I think it's still probably some of the best science fiction ever produced—but as powerful and exciting as they were to someone who knows the show, these last few episodes would have been completely incomprehensible to a newcomer. I don't think that's a terrible thing, as I have a great affection for serial fiction, and I don't think that it can even be completely avoided while still producing a compelling drama. There's just not enough time in 44 minutes to set up enough backstory to produce stories that are rich enough. (Comedy has an easier time here—The Simpsons and Family Guy are still pretty self-contained.) It's starting to make me glad that the show is coming to an end in ten more episodes or so, though. It's an excellent show, and I'd hate to see it collapse under its own ever-increasing weight.
Heroes was worse. I first saw the fourth episode or so, and by that point the show was already baffling and impossible to follow, to the point that when I saw it after the preceding ones in the proper order, I barely recognized it.