I chose The Devil Wears Prada by Lauren Weisberger (and no, not because of the film).
Wikipedia says:
The Devil Wears Prada (2003) is a best selling novel by Lauren Weisberger about a young woman who, freshly graduated from college, is hired as a personal assistant to a powerful fashion magazine editor, a job that becomes hellish as she struggles to keep up with her boss's capricious and demeaning requests.
I adored this book. It isn't exactly intellectual and it's not going to win any awards, but I laughed all the way through it. I think it's well written and, for those of us with bosses-from-hell, it definitely rings true. It is miles better than the film as well.
Happy reading.