Iain M. Banks's Culture novels are the best of the modern space operas. Centering on the Culture, a post-scarcity utopia devoid of hierarchies and overseen by hyper-intelligent AI Minds, they tend to focus on clashes between the ideals of the Culture and other galactic civilizations. For that reason, the novels center around Contact and its secret service Special Circumstances, whose goal is the delicate balance between nudging other civilizations towards the Culture's philosophies without becoming conquerors themselves. The Player of Games, the second Culture novel to be published, places this conflict front and center with the game of Azad.
With a certain amount of subterfuge, Contact orchestrates the Culture's greatest game-player, Jernau Morat Gurgeh, to visit the Azadian Empire, a rare interplanetary empire that has managed to cohere together around Azad, a game used to determine fitness for government positions. Azad is a fantastically complex board game, played on three giant boards hundreds of meters across, and capable of encoding philosophies and politics in the gameplay. The driving force of the novel once Gurgeh arrives in Azad is the clash between Gurgeh's Culture-influenced philosophies and the Azadian imperialist philosophies, both on and off the game-board.
This probably makes The Player of Games sound like a dreadfully cerebral novel, and while it's true that in Culture novels the principle character is the Culture itself and they're more about the ideas discussed rather than the characters discussing the ideas, they also have a wicked-sharp sense of humor (the Minds in particular are thoroughly absurd beings, and they have the best names) and Banks never gets bogged down in technical sciencey details. They're effectively highly accessible critiques of contemporary society and cultures framed in science fiction trappings (it's hard not to look at the excesses of the Empire of Azad and see a distorted view of our own culture in it), and the Culture itself is a wonderful ideal of an oppressionless society that, while probably impossible for humanity to attain, is certain to poke some minds into thinking outside our society's boxes.
The Player of Games is a perfect book for that intellectual sort of gamer, the one more likely to play Civilization over Call of Duty (though prepare for them to suddenly and terrifyingly realize why and how Civilization has the mechanics it does); even a non-gamer interested in political ideas and cultures outside of capitalism is going to get a lot out of this (or any Culture novel). Banks isn't afraid of disturbing imagery and violence in his books (especially when looking at the darker sides of Azadian culture), so be advised on that count.