I haven't seen anything as good as SG-1. I was never able to get into WH13 or Dr. Who, and to be honest, as soon as the Ori came into the picture for SG-1 and the spin-offs, I lost interest.
I have had success finding a couple random scifi series on Netflix though. There was a BBC one about refugees from Earth going to a distant planet, and only a couple of the colony ships made it, and there was a group of genetically modified humans who had been cast out who basically become the bad guys. There was also some interesting stuff on the planet, but I don't want to drop spoilers. Can't for the life of me remember what it was called, sound familiar to anyone else?
I also suggest Solaris (movie) if its still up on Netflix. It's not action, more philosophical? It was good regardless.
If I'm suggesting other shows:
Farscape
Battlestar Galactica
Outer Limits (old and new, neither are on Netflix afaik)