Interesting. I've made it a point to try to make my way through the canonical sci fi greats over the years, and I'd put Left Hand of Darkness near the top. It's kind of because of that tonal difference: there's something about the way it's written (sort of anthropological / travelogue style) that makes me feel truly immersed in the culture and world being described, in a trance-like way, even though the book itself doesn't have particularly exciting events in it.

It may be that it hit me at a particular time in my life: I read it in my early teens and the way gender was expressed in the novel, the sort of tidal shift between masculine and feminine based on circumstance, really spoke to me at a time I was figuring all that out in my own psyche. I wonder if a lot of the gender exploration in the book may seem more trite and typical now.