What makes a good book?

The answer to this question is different for everyone of course. I like that I'm doing a lot of reading this term. And I don't even mind that I like some books better than others; that's inevitable. Right now I'm reading A Single Man by Christopher Isherwood. Once I get it done I'll watch the movie. I'm hoping I like the movie better than the book, but I'm frankly not holding out a lot of hope. In fact if someone plopped this book down on my desk and said, "We'll hire you to adapt it." I would have no idea where to begin. I'm just over half way through and I have to make myself keep reading.

There are moments that I love. The book is peppered with these brilliant descriptions of things.

"If eating is regarded as a sacrament, then the faculty dining room must be compared to the bleakest and barest of Quaker meetinghouses."

and when the main character - a man in his 50s, feeling old, but alive - is looking at himself in the mirror at the gym

"And, as long as he doesn't have his spectacles on, he can't see the little wrinkles inside the elbows, above the kneecaps, and around the hollow of the sucked-in belly. The neck is loose and scraggy under all circumstances, in all lights, and would look gruesome even if he were half-blind. He has abandoned the neck altogether, like an untenable military position."

My problem is that in spite of the fact that I like the main character, and I like the language used in the book, I'm 100 pages in and NOTHING HAPPENS. I'm bored. So clearly, for me, a good book has to have both a character I can engage with, and a plot.