Heart of the Matter (Emily Giffin)
I've read all of Emily Giffin's books and I'm a big fan, though I was a bit disappointed by her last book, Love the One You're With. Her more recent book, Heart of the Matter, was more enjoyable for me. My only complaint is that I felt she really developed the two female characters (Valerie and Tessa), but gives the reader no insight into the male character (Nick) and he plays a huge role in the book (as you'll see if you read it) I was frustrated that we don't know his side of the story or his feelings, as the story is told through the eyes of the two women.
If you've never read any of Emily Giffin's books, I highly recommend Something Borrowed and Something Blue.
Up next: Friday Night Lights, by H.G. Bissinger