Actually, I dont care for giant space battles I started watching it out of interest, but quickly found interest in the sub-plots with the characters and how they deal with life in a migrant fleet fleeing from the enemy much more interesting.
Sci Fi for me is something that can easily be done wrong. Ive never had an interest in things like Andromeda, Firefly or Babylon 5, Every crime in the book from boring characters, to cheesy stories, cheesy ideas, right down to having no direction at all which series like Heroes are being criticised for.
BSG for me has been a dark, dritty, political and sexy (not in the litteral term) program. Its worth watching from the start. It changes pace often and you wonder where it is going, but it allways finds direction, right now its just gotten interesting again, it was one of those episodes I like to think that rewrites the way things are and sets the scene for something to come. Your not thrilled by it but your left intrigued.
It makes you think someone is something for the first 35 minutes and bang right at the end slaps you with the real truth or revelation.