The Dispossessed by Ursula K. Le Guin

The novel is a profound exploration of two vastly different societies on twin planets, Urras and Anarres. The protagonist is a brilliant physicist from Anarres, a planet with an anarchist society, who travels to Urras, a planet with a capitalist and authoritarian regime. The book explores his struggle to reconcile his anarchist beliefs with the stark realities of a different socio-political system. It's a thought-provoking investigation of human nature, power structures, and the idea of utopia.

The 1327th greatest book of all time