Author: Ursula Le Guin Winner of both the Hugo and Nebula Awards back in 1970, The Left Hand of Darkness is set on the planet Gethen - also known as Winter - and follows a Terren native known as Genly Ai, a telepath whom has been directed by the Ekumen to bring the inhabitants of Winter into the intergalactic coalition of humanoid worlds. Unfortunately, he quickly discovers that Karhide and Orgoreyn (the two major kingdoms of Winter) are both hesitant to accept his invitation to join the Ekumen, and he is imprisoned in a labour camp for his trouble. One of the most interesting aspects of The Left Hand of Darkness is its treatment of gender, which is often described androgynously and without explicit consequence. Though Genly Ai is described as being characteristically male, the Gethenians themselves are impossible to categorise in the same way, often being comprised of both typically masculine and feminine personality traits, and existing seamlessly between male and female classifications. Its even suggested that Genlys difficulties negotiating with the Genthenians comes directly from his misunderstanding of their sexuality, which is perhaps one of the reasons that the book still feels so prevalent today. Regardless, it's a hell of a novel and perhaps Ursula Le Guin's finest to date.
