A good science fiction novel about left-wing anarchism (see also anarcho-syndicalism, as opposed to the capitalistic oriented right-wing anarchism of Ayn Rand and most libertarians) is The Dispossessed by Ursula K. Le Guin. It's a good novel, because it's well written, and it's good science fiction, because it brings to life the reality of anarchism, and not only the positive or negative side.

(BTW: Why get left-wing nodes bad reputations all the time?)