Recently re-read 2010. This used to be one of my favorite books that I would read over and over in high school, and I was curious how it would hold up. I remember liking the post-Cold War sensibility of the book with the Americans and Russian cosmonauts working together, even though back on Earth the two super-powers are locked in conflict.
I find the book remarkably soothing...I think because at least half of the book is astronomy and physics: orbital mechanics, descriptions of the various moons around Jupiter and where they are in relations to each other figure largely. It's like everything I love about the sky show at the planetarium.
I had forgotten how weird, how truly weird, the transhuman Dave Bowman chapters are, but my hat is off to Clarke for taking an enormous risk in going there. Also his thought exploration of things beyond our knowledge, like the core of Jupiter or the watery world under the ice of Europa. One of my favorite parts, oddly, which isn't included in the movie, is the Chinese astronaut's last account of the destruction of the Tsien on Europa and the flowering spores.
I also love how Clarke's 2010 really embodies the evolutionary biologist J. B.S. Haldane's view, which he quotes in the book, "...my own suspicion is that the Universe is not only queerer than we suppose, but queerer than we can suppose." So much of the mystery and suspense in the book is a lack--the monolith's non-responsive presence that defies human attempts to understand and communicate with it. Human beings are drastically scaled down to one form of intelligence, and a not very advanced one at that, in a universe that is stranger than we can imagine.