Funny that most of the comments are about the name. What an excellent choice.
The first book Consider Phlebas isn't bad, but it isn't as well developed as the rest of the series IMO.
My reaction is perhaps summarized by the old quip: "This is not a novel to be lightly tossed aside. It should be thrown with great force.".
It wasn't any one thing but I eventually hit a point where continuing just wasn't worth it for me. There's too much else on my to-read shelf which is less likely to seriously annoy me.
Stephen R. Donaldson: He's more known for The Chronicles of Thomas Covenant, but you might prefer The Gap Cycle; it's more typical SF.
Also, the Night's Dawn trilogy by Peter F. Hamilton. Perhaps Dan Simmons? And of course anything by Charlie Stross.
Does it get better in the later chapters?
I know Use of Weapons doesn't depend on any of the other books for its plot, but is it a decent intro to the setting? If it is, that's where I'd recommend starting.
Use of Weapons is more than a decent intro, but I'd still personally recommend The Player of Games since it isn't as deep and heavy in comparison, and the narrative structure is simpler.
Of course, YMMV, but I started with TPoG, and reading UoW right after it was absolutely fantastic. I guess my biggest concern with recommending UoW as the starter would be that it might diminish TPoG, which I'm fond of, but I don't know if it actually would, since they're connected pretty much only bound by the setting.
My favorite by far is Excession but I don't know that I'd start there. I think the payoff of getting a story from the perspective of the Minds is better appreciated after you've heard about them and their capabilities from a distance in the preceding books.
My pick would be to start with Player of Games. That's the one that was a page turner for me nearly from the jump.
I enjoy the settings and the concept of the Culture more than the plotlines.
I like 80% of his work, 15% is a pointless depressing slog, and the other 5% is just too much for me.
Really, Culture is a great setting for discussing a lot of interesting philosophical questions and topics.
What cool is that Paradox's Stellaris, a civ-in-space game, definitely takes pages from Ian's Culture series.