There aren’t many authors with universal acclaim across the sci-fi reading community. Iain Banks is one of them, and the Culture series is his masterpiece.
The Culture is a post-scarcity civilisation run by benevolent AI “Minds” — and the series explores what happens when that civilisation interacts with ones that are messier, more violent, more recognisably ours. It’s utopia written by someone smart enough to know that utopia is boring — so every book finds the cracks.
Use of Weapons has one of the most devastating structural twists in any novel I’ve read. Player of Games is the best entry point — tight, focused, and it captures the essential Culture tension: what does a society that has everything do with itself?
What Banks does better than almost anyone: he writes AI characters (the Minds, the drones) that are more compelling than the humans. They’re funny, arrogant, manipulative, and occasionally terrifying. The ships name themselves things like So Much For Subtlety and Falling Outside The Normal Moral Constraints. That tells you everything about the tone.
Start with: Player of Games or Consider Phlebas. Peak Banks: Use of Weapons, Excession.