I was kind of conflicted between Kafka on the Shore and Hard-boiled Wonderland at the End of the World, but I was slightly leaning towards Hard-boiled Wonderland. I get the feeling that it will be a little bit lighter and faster paced. Also, his newer novel, IQ84, sounds really interesting. It seems to be getting very mixed (love it or hate it) reviews on goodreads, but I get the feeling that most of the complainers don't like his books much anyway, or started with IQ84 and found it was too abstract for their liking. All the things they're complaining about were present in TWUBC, and didn't bother me in the slightest, so I get the feeling I would like it.