The way i've heard BSG described is a drama just in a sci fi setting. It's not really about phasers and aliens and stuff, rather it deals with some pretty heavy topics about morality and ethics and justice along with an astounding plot and great characters. I never watched star trek, and I didn't even like Star Wars growing up. This is about the only sci fi show I watch, but it is amazing.
you guys who do watch the show and have seen the season 3 final episode, this is a great read:
http://www.post-gazette.com/pg/07085/770732-352.stm