Hyperion and The Fall of Hyperion, by Dan Simmons, are one strange, fascinating story in two volumes. I hope that Jo Walton decides to re-read it when she comes to it in her Revisiting the Hugo Awards Nominees blog series on the Tor website (Hyperion won a Hugo and The Fall of Hyperion was nominated).
Spanish cover of Hyperion by Dan Simmons, via Virao del Casco’s flickr.