Ursula K. Le Guin, The Dispossessed: An Ambiguous Utopia (1974). Le Guin's fairly brilliant imagining of a well-established revolutionary anarcho-syndicalist society. Demonstrates why it makes sense to save your hardest criticisms for your own prescriptions. Books like these are really carrying the whole SFF team.
There has been a huge amount written about it, and because of it. And for now at least I won't try to add anything to that.