I rarely give any show or episode a rating of 10, but this is a rare exception. Rather than concluding the series with a hokey truce with the Cavil Cylons or some douchy time travel cure-all, they elegantly tied up all of the loose threads while still leaving enough to the imagination that each viewer can interpret some of the elements according to his or her own perspective. I'd go into greater detail, but I don't like posting spoilers and I would certainly have to if I were to discuss Starbuck, Hera, Baltar's vision of Caprica Six and Caprica Six's vision of Baltar. The revelation of what "All this has happened before and will happen again" meant in the end was very nicely done. It had leant to the misconception that some form of time travel would have been involved. I'm so glad that was not the case. One thing that Ron Moore had desperately tried to stay away from throughout the series was what he called "Star Trek solutions" in which some super-advanced bit of technology is used to save the day.
The performances by the principle cast were awe-inspiring. Mary McDonnell and Edward James Olmos delivered Emmy-worthy performances. I would be genuinely shocked if they were not both nominated.
The part that I loved the most was the theological questions they deliberately left somewhat vague. Since the human race in the real world has been struggling with the concepts of religion for millennia, why should BSG wrap it up neatly with a cute little bow on top?
Too many series use the storytelling technique of force-feeding the morals of the story to the audience. This show was much more subtle. I'm sorry it's over, but I'll be forever grateful that it was made.