The player of games

This is the first Iain M Banks novel I've read and I really enjoyed it. It's big far future space opera, but the focus is on the characters (some of them AI drones). The pacing is great with peaceful sections interspersed with violence and threat building to a satisfying conclusion. 

The external exploration of a fascist empire from the point of view of a culture game player gives deep insights into the political philosophy of both, and the author himself. The ending leaves a sour taste in your mouth, with a lot of moral ambiguity on who was "right".