Dune

The Dispossessed Ursula K. Le Guin

A physicist from an anarchist moon travels to the capitalist planet it orbits -- the first person to make that crossing in 170 years -- and is changed by both worlds.

A Canticle for Leibowitz Walter M. Miller Jr

Monks in the post-nuclear American desert preserve the fragments of human knowledge across six hundred years of civilisation's slow return -- and its equally slow drift back toward catastrophe.

The Left Hand of Darkness Ursula K. Le Guin

An envoy from Earth visits a planet where people have no fixed gender -- and learns how much of politics, trust, and love depends on it.

Children of Time Adrian Tchaikovsky

The last human survivors search for a new home -- and find a planet already claimed by a civilisation of rapidly evolving spiders.

The Three-Body Problem Liu Cixin

A physicist investigating a series of suicides discovers that humanity has been contacted by an alien civilisation -- and some people are trying to help them invade.