Consider Phlebas, Iain M. Banks. Orbit, 1987/2008
The Culture is Banks' future post-human Utopia, of sorts. People in the Culture can change their gender at will, secrete a variety of drugs from genofixed glands, don't use money, and have hyper-intelligent machines. The Culture's machines, unlike those in, say, Terminator, are fairly benevolent, and the Culture's people are happy living under them, in their hedonistic paradise.
The Culture's spaceships are controlled by Minds, one variety of the hyper-intelligent AIs.
Consider Phlebas looks at the Idiran-Culture war, which is a war of principles. The Idirans are a war-like species (think the Klingons, except tripedal beetle-lizards) who are immortal religious zealots and consider the Culture an inferior species. The Culture sees the Idirans as a threat to their lifestyle and expansion throughout the galaxy.
Bora Horza Gobuchul is a Changer who works for the Idirans. Changers are a subspecies of human, who, as their name implies, can alter their appearance at will, to resemble someone else. He doesn't like the Culture's reliance on machines and thinks their plan for life is too sterile, and inhuman.
Perosteck Balveda is an agent of the Culture's Special Circumstances division, a sort of spy, who is trying to stop Horza.
A Mind escapes from an Idiran attack and hides itself on a Planet of the Dead: a place where the people wiped each other out millenia ago. Planets of the Dead are guarded by Dra'Azon, a highly advanced species. The Idirans want to get their hands on the Mind, because it's Culture, and they want to control it. The Culture wants to get their hands on it, because it's more advanced than anything else they'd had before.
Horza used to live on Schar's World, so the Idirans task him with going there. He joins up with a hapless troop of mercenaries, and he sets about his task, with misadventures befalling him along the way.
The text is quite long -- 515 pages -- but it doesn't drag. Banks is good at dropping hints and picking them up chapters later. It ends on more of a downer than I prefer for books I read, but it fits the story, so I won't complain.
I've also read The Player of Games (more game theory than I cared about, so it was kind of boring) and Excession (wherein the ships take center stage, and I enjoyed it greatly.)
If you like space operas on a grand scale (where the ships travel kilo-light-years per hour), pick up some Banks.