I had difficulty with this one.
In all honesty, I'm not sure how much of that difficulty was cultural; TheThree-Body Problem doesn't, quite, feel like a novel geared to Western expectations of narrative (which isn't, of course, a bad thing). The actual plot is as hard as it's possible for hard SF to be: a scientist is drafted into a strange war, one which sees fellow scientists committing suicide left, right and centre, one which seems to hinge on a strange computer game which asks participants to solve the titular three-body problem, a real-world mathematical conundrum concerning how three bodies in space (e.g. three stars) interact. It's almost impossible to solve, and that forms, essentially, the crux of the novel. There are also aliens.
And all of this is set against the background of the Chinese Cultural Revolution, which opens up all sorts of interesting parallels with the truths revealed in the last third of the book. It was this last third that saved The Three-Body Problem for me, though I think I'll need more time with the text percolating in my brain to appreciate all those parallels.
Otherwise, the book feels strangely structured: we don't get any real pay-off from any of its various events - it feels more like a section of a long book than a novel in its own right, and on finishing it I do feel a bit unsatisfied.
But I'm glad I read it, even if I, personally, failed to click with it.