Not only the original for 1984 and Brave New World and the other dystopian novels, but better than them too, in my view. Some people have knocked it for its complexity, for its comparative lack of plausibility, but the truth is that "We" is far more subtle, and its society is far more unsettling and terrifying. Some have criticised the translations, but I found the Penguin translation very good and readable: Zamyatin called it a "prose poem", and it had that quality, particularly when read aloud.
The narrator is not like the comparatively rational but disaffected characters of 1984 or Brave New World, he is a deeply confused, emotionally traumatised atomised ant, trying to gain some control over his thoughts and feelings to find a way to crawl out of his suffering. It has both the sense of wonder of a good SF novel, while having at times the psychological feeling of Dostoyevsky.