I didn't even think there were 50 notable science fiction shows.
How about Deep Space Nine and Firefly getting beaten out by fucking Voyager? That should've been your first tip-off that this list is bullshit, Nacho. Fuck, looking over this, I don't even see Deep Space Nine. Even Enterprise had better moments than Voyager, towards the end of its run. Firefly? Beaten by Voyager? Christ. Voyager had a continually declining fan-base. Firefly has a movie coming out, and they started mostly from scratch. All the Buffy fans in the world couldn't save Firefly though.
So, Farscape, DS9, and Planet of the Apes not even listed, and Voyager edges out a ton of far better series. Buffy the Vampire Slayer at its worst was better than Voyager (great run-ins with the Borg? They ruined the most impressive species ever encountered). This isn't a list of the top 50 sci-fi shows. It's a list of a whole bunch of shows that are loosely fantastical and done solely to get the Globe attention.