Fascinating alien society that shines a big old spotlight on our own gender hang-ups, plus the shocking twist at the 25% mark of having an emotional through line? Le Guin does write like a misogynist 60s sci-fi writer but I'm willing to attribute most of that to the main speaker's character arc. I hope Earth has an Estraven prime minister ready when the aliens come.

Strongly considering buying the physical book just to change all the pronouns to xe/xir or something and then knocking my head into the wall so I can read it for the first time actually seeing the Gethenians as the 'ambisexual' beings they are without the baggage that comes with he/him.