Revolutionary Road by Richard Yates.
I could hardly put this book down, and I can't wait to see the movie-though of course it will be a huge disappointment compared to the book.
The story of an average American marriage in the 50's-the choices we make, the sacrifices we make, and how it can all blow up in your face.
I LOVED this book. And the twist at the end caught me totally by surprise. Read it.