I've lost track of the number of times I've read this book - it easily exceeds ten. I hadn't read it for a while, but Le Guin's death recently has sent me back to her works. I wasn't overly enchanted with revisiting The Left Hand of Darkness, but this one remains one of the best fantasy novels ever written.
After I wrote that paragraph, I went to Wikipedia on the book to look up a plot point, and discovered that many, many people agree with me on its qualities. If you haven't read the book, don't read the Wikipedia entry though: typical of Wikipedia, it has spoilers completely free of warnings.
The story is a coming-of-age tale of the young man Ged who, we are told, will be one of the greatest wizards to ever live. He has a huge amount of innate power - and a great deal of pride. The book is full of lessons: his pride gets him into an immense amount of trouble. But LeGuin never lectures, she just moves on with the story showing the consequences and eventually the very difficult resolution.
The prose is plain, but also beautiful and very effective. There are many wonderful passages, but one that affected me deeply when I was young still reminds me to this day how differently we see each other:
Ged watched him with wonder and some envy, and exactly so he watched Ged: to each it seemed very queer that the other, so different, yet was his own age, nineteen years. Ged marvelled how one who had lived nineteen years could be so carefree. Admiring Murre's comely, cheerful face he felt himself to be all lank and harsh, never guessing that Murre envied him even the scars that scored his face, and thought them the track of a dragon's claws and the very rune and sign of a hero.
The book is one of the cornerstones of fantasy, and a wonderful piece of literature.