A number of really good franchises, but I had to go with Stargate. SG-1 and Atlantis were great shows and lots of fun. I wish they bring it back with another show of that caliber. SG Universe only started getting good at the end. The whole first season was a snoozefest.
Star Trek. Easily the most intelligent franchise ever. Love Stargate, Star Wars, Doctor Who too.
I think Star Wars and Doctor Who are a lot more fantasy than sci-fi to win the "best sci-fi franchise" crown.
And though I am sort of Alien/Predator/Terminator fetishist, their universes are too small to compete with the others.
Star Wars. And yes, the prequels were masterpieces as well. (Well, Episode II and III anyway.)
Well...They were. I have seen them again and again and again and fail to see why people hate them other than bitter nostalgia and failure to embrace the new. I could go on for HOURS about why the prequels were masterpieces and how they are some of the best sci-fi films ever. I really could, and could counteract any attack a bitter fanboy may have against them.
Not a lot a big "classics" here, however I notice Dune for example. So if Dune is part of your criteria, what about Foundation (Isaac Asimov), The Culture (Ian M Banks) etc, etc...
It would have been more logical (in my opinion) to remove form this list: Dune, Ender and Douglas Adams. It would have been more consistent I believe...
I have a professionally framed print depicting the First Cylon War hanging over my computer desk as I type this. I feel compelled to vote for Battlestar. I'm really only a casual fan of Star Wars and Star Trek. And even though Alien is one of my all time favorite movies, its also the only one I like outta the whole bunch.
At first I was going to say Gundam, but when I really thought about it, there's not a lot there to explore because every series has a distinct ending that pretty much renders the Mobile Suits no longer practical, and a sci-fi universe whose story ends with the destruction of the main element that makes it a sci-fi universe loses it's luster. It would be really cool though to be able to see the mobile suits in their prime though, but once the war ends and peace time is abound the mobile suits normally have a nasty habit of "blowing up".