The title of the thread is not "What is the best science fiction television series?" but "Determining what is the best science fiction series?"
So it is not really about voting it is about determining criteria.
An example from Star Trek is the SOLITON WAVE....It is the difference between SCIENCE Fiction and sci-fi and fantasy.
psik
There are those who like exotic daydreams, and find the outside world uninteresting or intimidating or an irritating distraction from navel gazing. This set usually doesn't know much about nature or society or people in general. So, discovering there is really is a soliton wave has no more esthetic appeal than anything else outside their egos. (None, apparently.) If the real world is irrelevant, then science fiction that tries for its kind of relevance, a reasonable adherence to science, is irrelevant.
But that appeal of science fiction, its potential relevance to the real world, is as much an illusion, an artistic effect, as anything else in fiction. Real science is indeed found in textbooks. Speculation is an indispensable component of real science, but untrammeled speculation can easily lapse into crank science. In science fiction, where the science is speculative (aka fictional) and therefore unrestrained by brute experimental facts, that means that there can't be any rigorous criteria. The ignorance of the reader, the ignorance of the author and the ignorance of the scientific community about the many remaining secrets in nature all conspire against a rigid definition.
Not only that, it being pretty much impossible for a single author to answer all questions, it is pretty much mandatory that some difficulties get finessed. H.G. Wells imagined the end of the world as rigorously as he could, then finessed a time machine to take one of "us" to see it. Also, authors indiscriminately borrow the props, often called tropes, in previous sf works, tacitly assuming the rationales. The force of tradition keeps them around, even as it becomes more and more clear how preposterous they really are. Space war is a good example. A definition of science fiction that changes with progress in science isn't much use.
The notion that goodness in science fiction should be defined in terms of what science fiction, as a unique kind of art, can do is a powerful one. Speculation about nature is something science fiction (and no other kind of fiction) can do is a perfectly reasonable thought. A closely related notion, maybe identical, that science fiction (and no other kind of fiction) can project the consequences for people of scientific change, also is perfectly reasonable.
There is a problem for any definition of science fiction in terms of its esthetic function. Which is that hacks write to marketing categories. They define their work in marketing categories because they are interested in sales. Adverse criticism may have no effect on sales but they are not disposed to take the risk. Therefore no definition in those terms will ever be accepted. No argument is powerful enough to overcome vested interest. Only integrity can do that.
In marketing terms, fantasy and science fiction blend together because lots of people dislike any thought of the fantastic. It offends their certainty that mundane reality is all there is. They can't suspend disbelief, and that's just all there is to it for them. SFX can substitute for suspension of disbelief which is why there's more scifi in movies. But for print, herding all the weird stuff into a category is helpful for the consumer.
Now, it is true that there are no ghosts, talking trees, wizards etc. Whereas it is true that in fact science and technology have, and will continue to, made great, and seemingly fantastic changes. But ignorant people are ignorant of history. For some, fantastic is fantastic. It's all just technicolor for their navel gazing. (The most genres in fantasy and scifi are boys' adventure and romances, both notable as mostly daydreams written down.) For these people, science fiction, fantasy, it's all the same. It's basically the same kind of phenomenon where people are completely indifferent to whether the grammar is intelligible. You know, the kind of think usually called "style." They're basically tone deaf.
For most, in practice, the outward directedness of science fiction gives it an entirely different esthetic experience than the reality shunning fantasy. Which is why the people who like fantasy romances in the various styles of Charlayne Harris, Laurel K. Hamilton, Sherrilyn Kenyon et al. don't generally read the science fiction romances of people like Catherina Asaro, the late Kage Baker, Justina Robson or Sandra Macdonald.
The terms genre and subgenre have been misused in duplicitous debate. "Genre" sometimes means a type of story, like horror or mystery. This usage actually has a coherent meaning. Other times "genre" means a particular marketing category, useful only when wandering through a bookstore.Other times, "genre" is a loaded term, meant to imply sensational, melodramatic, simplistic, essentially
popular. Statements like "Science fiction is a subgenre of fantasy," can't really mean much except "Fuck you for pretending to have standards." The implicit statement is "Literature is a subgenre of realism." Which makes the insult intended obvious as the expense of showing how stupid the thinking is.
My apologies for getting long winded. People called out to work Christmas Eve, people falling, snowstorms wrecking holiday plans, light fixtures crashing to the floor and people walking on glass. Things haven't gone smoothly and stating the obvious is such a soothing exercise, I couldn't resist.