I was surprised to see that no one had reviewed The Dispossessed on this website, given that it is probably one of the best science fiction novels ever written, therefore I am submitting this review as a recommendation.
I think Le Guin has an undeserved stigma of being a 'soft fantasy' author and she never seems to get a high placement in book shops or bestseller lists. This is strange, given that she is still writing now at a reasonable high level although I think even her die hard fans would admit that her heyday is probably over. She's not a prolific author but that makes her all the more impressive given that her titles are of a consistently high quality. I would also recommend The Word for World is Forest, The Left Hand of Darkness and the Earthsea Trilogy. However, although these are all fine titles, I think The Dispossessed is her best novel.
The plot begins on Anarres, the moon of the planet Urras, where a colony of anarchists (following the precepts of a female philosopher named Odo) have built their own society. Despite spartan conditions and a strictly ethical lifestyle the Anarresti consider that they have found paradise here and pity the 'profiteering' Urrasti for their material comforts. This is the basic setting but the story takes place in Ursula Le Guin's commonly used sci-fi universe in which advanced civilisations (headed by the Terrans and the Hainish) have formed a loose knit trading alliance and are slowly spreading world of their existence across the galaxy hampered only by the problems of communicating over relativistic distances. It has been a hundred and seventy years since Urras allowed the problematic Society of Odonians to settle the moon and in that time little has changed for them. Their society is roughly comparable to that of present-day earth: the world itself divided into a number of different power blocs and the culture a mixed bag of capitalism, communism and all the other philosophies in between. Historically their tyrants have been bloodier and more grasping than our own and present day Urras is perhaps materially richer than Earth and more misogynist but otherwise it's similar enough to be comprehensible.
However, it is through the eyes of Shevek, an anarchist from this Odonian colony of Anarres, that we see Urras and with his point of view the reader is offered his value system. The structure of the narrative is skilful. The novel begins halfway through the story with Shevek becoming the first Anarresti to visit Urras. It then moves back in time in the next chapter to begin the story with Shevek's childhood. Throughout the book Le Guin progresses each half of the story so that Shevek's journey to maturity (as a person, a scientist and as a rational entity capable of ethical decisions) is intercut with the main act of his life: his visit to Urras. In the last few chapters this concludes beautifully as the reader sees how Shevek makes the decision to go and the outcome of the visit in short succession. There's nothing confusing about the movement of the plot but this elegant structural twist adds a depth of interest to each different dimension of the story.
Shevek, the central character, is beguiling. He is a great physicist, the only such on Anarres, and at the point of his journey to Urras has been working on a theory of the general field in temporal physics: the Principle of Simultaneity. In short it is Shevek who will invent the 'ansible' - a Le Guin invention which allows instantaneous communication between vast stellar distances.
I shall briefly digress to say that Le Guin rarely goes into detail about the mechanics of her universe in any of her science-fiction novels. But she has a grasp of how to present a world to the reader which means that her science appears elegantly simple and unobtrusive. In her other fiction the idea of the ansible has often been significant in the plot. Her federation of planets is not rapacious because they are separated in space but the ansible permits them to form a coherent society and culture despite this. Orson Scott Card found the idea so attractive he picks it up in the sequels to Enders Game and discusses it in detail in his book on how to write science-fiction and fantasy.
Back to The Dispossessed and to Shevek, it's important to add that Shevek is an attractive as well as interesting protagonist. To a certain extant all Anarresti are philosophers; they are very much engaged in living a philosophical premise - that of erasing a concept of ownership from their hearts and minds. Unfortunately, in the years since the Settlement, the Odonian ideal has slipped a bit and many Anarresti have got out of the habit of anarchism. This is not true of Shevek whose dedication to, what is on Anarres, an obscure science has forced him to reassess the basic premises of his culture as he struggles to do the work he knows he is meant to do without compromising the rigid ethical standards of his society.
Despite the depth of information Le Guin includes, this book is not an arid treatise on philosophy, politics and physics. The characterisation is masterful, the plot is gripping and the background fascinating. It is truly what science-fiction should be: a believable story of an alien world. I give The Dispossessed the highest mark available to me on the Amazon ratings scale: five stars. There can be few pieces of fiction in any genre that are better than this. I certainly don't believe that I've ever encountered a book more deserving than this one of any accolade bestowed upon it. If The Dispossessed has a flaw it is that it ends.