The Glass Bead Game (sometimes called Magister Ludi in earlier English translations) is a book my husband has been pushing me to read for quite a while. It's huge, but it actually didn't take me all that long to get through it. (Although, full disclosure, I am still reading the short stories/poetry that is included at the end of the book.)
I enjoyed this book, but at the same time, I'm not at all sure what to make of it. For one thing, I kept feeling as if the author had his tongue in his cheek, but in a way so subtle that I kept missing it (and thus feeling very stupid). Part of that is due to the overly serious academic style--I'm almost sure that anyone who can do that this well is doing it half in jest.
It's the story of a scholar as he moves up the ranks of an elite intellectual class, learning, teaching, and mastering the nuances of a unifying and almost spiritual exercise called the Glass Bead Game. There's a lot of really meaty philosophy here, along with some startling commentary on the serenity and yet barrenness of solely intellectual pursuits, contrasted with the messy, needless pain of the active life, even though it is more useful to the world at large.
What I most enjoyed was tracing the long tangle of the protagonist's views on these two worlds. I'm a sucker for stuff like that, all the way from Disney's version of The Little Mermaid to Life on Mars to Charles Williams' spiritual thrillers.
If you're likewise interested in the struggle between active life and the intellect, or are an intellectual yourself, you will also enjoy this book. Don't be afraid to take it in small chunks--it's not paced for a direct read-through, and parts of it benefit by contemplation afterwards.