I am a fan of harder, darker Sci Fi, so for me there are plenty of franchises that stand out above Star Trek and Star Wars. Of the Stargate series, I much preferred SGU, because of the darkness, otherwise I found it simmilar to the other big franchises. I loved Babylon 5 because of the amount of detail in the story, the richness of the characters and the massive story arc. Also a big fan of Farscape for the utterly alien nature of things, including the characters. And, even though I am far from being a Browncoat, I will put my vote in for Firefly for the less heavy end of Sci Fi. Add in Doctor Who to the less heavy mix and I think that's my top list.
"Listen, or your tongue will make you deaf." - Native American Proverb