Cetaganda (Bujold, Lois McMaster) 1996

Working through the omnibus versions of the Miles Vorkosigan saga, and so reading by the in-universe timeline rather than publishing date.  Cetaganda is a solid murder mystery with terrific cultures in conflict being worked out, to go along with Bujold's staples of witty dialogue between likeable characters who are having the worst Bujold can dream up thrown at them.  In Cetaganda, she also got the pacing and scene changes just right so that it's really hard to put down.  A worthy Nebula finalist.