Star wars is without a doubt my favourite sci fi universe with the 40k mythos being a close second.
What makes it for me is the fact that lucas's 'used future' look makes the world(s) seem believable, little things like having to bang the falcons panels to make it work (percussive maintainance), carbon scoring, dirt and grease everywhere... rebel flight suits with oil patches on the knees... the fact Lukes speeder is worth less when he tries to sell it because a newer model has come out.
I can live with the plot inconsistancies and i'd even take the prequels over other movie franchises because of this beleivable universe.
As a kid i liked Buck Rogers and Battlstar galactica but the originals dont really hold up so well know. the remake of BSG started off quite well but then just became a lame soap opera punctuated by cool space fights (except 'razor' that was an epic episode)
I dont hate star trek but its always been too peaceful , too clean, too many non violent and unrealistic solutions.
Star gate i coudl never get into past the movie, dont know why...
Other sci fi i love is the Aliens franchise and Firefly... i guess i just love the dirt ![]()
So what makes you go for your 'brand' of sci fi?
(oh and l like blakes 7 and Dr who from the 70s and 80s which were actually quite clean but hilariously low budget.. i think i like them for nostalgia reasons and the fact that most the scripts are really really good and original at the time)