My Review of A Storm of Swords
As this is a series that's very much in the zeitgeist right now, and one that a lot of people are progressing through at different speeds (and across different media) I'll stay away from spoilers, but believe me when I say that there are a LOT of twists and turns and surprises in this book.
To restate a thousand other reviews, though:
Martin's world-building is second to none. It's not the least bit difficult to believe that this is a civilization with thousands of years of history, some of it laid out explicitly, much more of it only hinted at.
To put into words just how great this series is:
It took me months and months to read this book, I have two more to go in the series as it stands, and I'm already aching about the fact that I'm going to have to wait for (surely) years for its completion.
Look, this is the GAME OF THRONES series, people. I don't have to spell it out for you. It's great, and you'll love it.
Unless that kind of thing isn't your cup of tea, but even then you still might.