The Hearing Trumpet by Leonora Carrington
A deaf old woman stages a rebellion in the bizarre old people's home to which she has been consigned by her stuffy offsping. What I remember most about it is that the woman is dissolved by the great goddess and her double becomes her. Carrington was a great English surrealist.Lolly Willowes, or The Loving Huntsman by Sylvia Townsend Warner
A spinster rebels against her tedious life and her stuffy nephew by making a pact with the devil, and thoroughly enjoys the experience. Warner was a socialist, and this is a political story.Night Watch by Terry Pratchett
I know Mr P is not a socialist, though he is a kind of soft lefty. This is a novel about revolution, and time travel. Well worth a read. It features Sam Vimes, my favourite Discworld character.Player of Games by Iain Banks
Yes, I thought I'd nab this as Mieville omitted it. Banks' gender politics are a bit threadbare on the whole, but I get the impression he wrote this before he fell out with his ex-wife. He takes the dehumanisation of modern capitalism and just twists it slightly so it looks new, by creating an interstellar civilisation where there are three sexes and political dominance is facilitated through a stylised game.Altered Carbon by Richard Morgan
Human consciousness is stored, transmitted through space, and implanted into (vat-grown?) bodies. All this just facilitates the oppression which reduces our bodies to commodities, and our labour to our only currency. Morgan says "Society is, always has been and always will be a structure for the exploitation and oppression of the majority through systems of political force dictated by an élite, enforced by thugs, uniformed or not, and upheld by a willful ignorance and stupidity on the part of the very majority whom the system oppresses."More than Human by Theodore Sturgeon
How human beings combine, deploying their various strengths and compensating for each others' weakness, into a whole more powerful than the sum of its part. This is the book from which as a child I learned the meaning of the phrase 'gestalt entity'.Always Coming Home by Ursula le Guin
I can understand this fictitious anthropology of a far-future low-tech anarchist Utopia will not be everyone's cup of tea, but I loved it when I read it, and I love it still. There are a lot of thought-provoking things hidden among the kinship systems and village maps.
Cloud Atlas by David Mitchell
Six interlocking stories, each told in a different genre style, including two types of SF. Each story is being read by a character in the story that follows, and then each story closes down again in order. Mitchell says 'The "cloud" refers to the ever-changing manifestations of the "atlas", which is fixed human nature... The book's theme is predacity... individuals prey on individuals, groups on groups, nations on nations'.
The Brief Wonderous life of Oscar Wao by Junot Diaz
The story of a Dominican-American SF fan, and his family misfortunes back in the Dominican Republic, under the oppression of tyrants like Trujillo. Probably more of a work of magic realism than fantasy, but I include it here because it's left wing, defiant of oppression, and it shows the intrusion of spirit totems into reality. I see from wikipedia that Diaz is active in the Dominican Workers Party.
Animal Farm by George Orwell
Some people think Orwell's books are anti-socialist. They could not be more wrong. Supposing one looked from man to pig, and could not see a difference - this is not to praise either pigs or men. It's saying that we don't just need to be free of these owners: we need to be free of all ownership.
OK I'll add one over the ten
The City and The City by China Mieville
People are separated and their ignorance of each other is encouraged for political reasons. This separation is enforced by secret police, who seem superhuman. But wait - the oppressive system only works because we all consent to it. We let ourselves be shepherded by people we imagine are stronger than us, but are really weak. If we threw off our chains, nobody could resist us.
Mieville obviously is a socialist. I don't think there's anyone on this list who is right wing, but their political beliefs range across the left wing spectrum. I didn't choose them on that basis, but I think right wing writers like Larry Niven or CS Lewis don't have so much to tell us about political reality.