Prisoner is an absolute classic.  Must see stuff. 

Since all fiction is fantasy in a sense, distinguishing Science Fiction from Science Fantasy is an interesting concept, but an accepted genre or sub-genre in many circles. I certainly think of The Lord of the Rings as firmly grounded in the Fantasy genre as the fantasy aspect overwhelms what science there may be (especially of a speculative scientific nature). At times it's horror... Tampering with nature is a common staple of the horror genre -- it's a transgression which deserves punishment... Creating the abomination of the Orcs was one of the most monstrous atrocities.

Science is about understanding the real world, fantasy is about creating imaginary worlds and peoples (flights of fancy), and the science fiction genre is concerned with imagining, or postulating, generally future or futuristic scientific advances/technology, as well as hypothesising potential social and environmental changes etc (note: this is where Delicatessan would fit). Or it can be just about having spaceships, aliens, and ray guns... The scientific method utilises observation and testing to better know the universe.... Experimentation in fiction and scientific experimentation differ. Science and fiction and science and fantasy by definition are at odds with each-other. Science is about trying to know the true universe, whereas fiction/fantasy is involved with making stuff up. Try utilising the scientific method by observing and testing within a fictional construct -- hard to do?. You can still hypothesise new developments/discoveries based with understanding of currently known scientific principles, laws, and theories, and then create a fictional framework (a story) to embellish it.

Fantasy, as genre, is often based on myths (superstitions etc,). There's often an element of mysticism, and irrationalism. Science tries to demystify what is a rational universe. Fantasy is magical, science is down to earth, and science fiction, while often scientifically informed, still, generally, has its head in the clouds, but usually there is a rational explanation for what happens. An awful lot of sci-fi might well be termed Science Fantasy... For instance, in so called fantasy genre works you have monsters, and so called sci-fi genre works many of the aliens are also monsters. Also, as the the technology may be about as effable as magic wands or rings, it may as well be of supernatural origins. Like fiction writer and scientist Clarke stated, "any sufficiently advanced technology is indistinguishable from magic"

So is the Lord of the Rings best defined as science fantasy, rather than "just" plain fantasy genre? And are the rings of power, for instance, best-described as technologically advanced tools, or as supernatural artefacts? I haven't seen the movies, since I loved the books too much, so I can only talk about Tolkien's vision. Tolkien was inspired/indebted by/to myths when creating the Lord of the Rings (mythical creatures, the Ring of the Nibelung etc.) I don't think he was particularly inspired by science, and therefore his books fall into the Fantasy genre as far as I can see, and is not really a hybrid of the science fiction and fantasy genres. If his rings of power were replaced with ray guns of power would that be enough to make it clearly sci-fi? As for the clear-cut science, or technology I should say: the technology in LOTR, it, if memory serves, is generally not particularly advanced. I'm thinking of Saruman's factories, though he did develop a new breed of Orc which was indeed science fiction-ish. On a side note: When it comes to "technological progress" in the Lord of the Rings, it takes something of a Luddite stance... Suruman's "industry" is bad -- it's against nature. He cuts down trees to feed Isengard's subterranean factory, he tampers with humanoids through crossbreeding (Sauron originally developed Orcs from men), and he pollutes the Shire with his factories. This was an anti-industrial message, we long to return to simpler pastoral times. That final chapter always reminds me of Blake's "dark satanic mills." Logan's Run and countless other books and movies, also had an anti-technology message. Where was I going with this? Science fiction generally looks to the future and often takes an optomistic approach to scientific discovery, whereas fantasy tends to look more, in a longing way, to the past. In its reliance on myth and magic, and it's idealizing of simpler times -- as in the case of LOTR.

Really there is no clear-cut definition of science fiction or science fantasy -- it's a semantics game and open to interpretation. Science, to use the Oxford defintion, is "a branch of knowledge conducted on objective principles involving the systematized observation of and experiment with phenomena esp. concerned with the material and functions of the physical universe." As I said before, fantasy as a genre is concerned with imaginary worlds and people. The SF genre is based on imagined, often future, techonological or scientific advances. All fiction/fantasy is a fabrication which requires the imagination.

I'd like to think of true, or hard sci-fi as speculative science... The imaginings should still follow scientific principles (scientific method). Of course under these definitions, you'll see that much sci-fi as well as fantasy genres deal with imaginary worlds and people, so the genres are not totally distinct. As I stated earlier, the sci-fi, horror, and fantasy genres are all concerned with the Fantastic in a way. I happen to look at Fantasy as more fantastic...

I suppose Sci Fantasy could also be used interchangeably in many cases with soft sci-ifi. Star Wars is a pretty good example of this. You might call it sci-fi or fantasy, or Science Fantasy (Sci-Fa for short)... It has imaginary worlds and peoples, and it has futuristic technology, though supposedly developed in the past, but it does not overly concern itself with visionary (fictional) science per se. Rather than trying to scientifically understand and elaborate on our universe, it deliberately distances itself in creating a "new" universe -- "long ago, in a galaxy far, far way." But that newness is indebted to oldness: Like the Lord of the RIngs, its heroic epic is indebted to old myths.

Now I'm off to watch an ASF (artsy science fartsy) movie.