Aurora, by Kim Stanley Robinson

Robinson is one of the top hard science fiction writers working today, and Aurora is another fine example of his work, though it didn't grab me quite as much as his Red Mars trilogy or 2312
The most interesting thing about this book is that the narrator is the ship. Through conversation with a couple key colonists and with the help of a quantum computer, the ship's various artificial processes are able to achieve, over the course of several hundred years, something very close to (if not actually) sentience. As such, seeing the humans through the ship's eyes provides the reader with a unique narrative experience, albeit heavy on the science and technology (which is Robinson's fan base anyways, and therefore quite appropriate). The last part is especially beautifully written, and I am once again impressed with Robinson's skill as a scientific as well as narrative writer.