I'm in the middle of Anathem at the moment, and finding it unputdownable. But then, I've just done a degree in the History, Philosophy and Sociology of Science, so that may make a difference.
I had to give up reading the Baroque Cycle while doing my degree because I was losing track of what was real history and what Stephenson had made up. His Isaac Newton is so good that I had to keep reminding myself that he didn't really have a room-mate called Daniel Waterhouse.