Lord of Light by Roger Zelazny
I finished this book a couple of months ago, and a friend asked me "How is it?". I just said it was the best book I had read in the last 10 or 15 years. It really is amazing.
The novel describes a war among humans that have acquired godlike powers during a centuries long trip across interstellar space. The people that obtained these powers have in fact set themselves up as immortal gods lording over a caste of mortal, powerless humans, and maintain them in a primitive state. The demi gods have taken on the names and aspects of Hindi gods, and implemented the wheel of karma with mind-reading machines and reincarnation devices.
Sam, the super-human protagonist, had been sentenced to death for attempting to lead the humans in a revolt against the gods, but is brought back to life by a few gods that want him to lead a new revolt.
The novel moves back and forth between a kind of beautiful epic poetry describing the lives of the gods and historic events, and a gritty prose when describing Sam's more down to earth actions. This contrast gives the novel extraordinary depth. It's even more amazing to think it was written in 1967.