I loved Sweet Valley Confidential. I've heard negative reviews for it, but I think that you have to take it for what it is: a follow-up to a pretty poorly written teen series. Don't go in to it expecting a Pulitzer Prize winning read.
Jessica and Elizabeth Wakefield are now 27. Jessica is with Todd Wilkins (omg!) and Elizabeth is heart-broken by their betrayal. If you have no idea what I am talking about, then this book really isn't for you. If you aren't aware of Sweet Valley, then it probably wouldn't be near as fun of a read.
I loved revisiting the Sweet Valley characters and was surprised by the paths many of them had taken. Some readers may find the developments in the characters' lives a bit far fetched, but I adored the story. I don't want to spoil the ending, but suffice it to say, I was very happy with where the Wakefield twins ended up.
Sweet Valley Confidential is a great read--if you already know and love the Sweet Valley characters and are able to put aside thoughts on the quality of the writing.