I konw James patterson is widely known for his mysteries, but I want to point out 2 books that are way out of his normal range of writing:

Suzanne's Diary for Nicholas
Sam's Letters to Jennifer

These are 2 beautiful stories (sentimental & somewhat mysterious, but not official "mysteries"). They are quick reads (although that could be because i didn't want to put them down!) but well written.

Just a warning though if you read them while using public transportation. I mainly read these commuting on the metro...I got some strange looks when I actually laughed out loud on ocassion, and at one point was standing in the middle of a packed rush hour train with tears streaming down my face as I read! (I actually had some sweet older lady ask me if I was OK.)

Hope you enjoy them too!