I have been on quite a reading kick lately, so this question is more difficult to answer than it would have been a couple years ago. However, there is one book that will always be my favorite. Always. Most people make have a pained expression when I tell them that this book is my favorite, but I have my reasons, I promise.
My all-time favorite book is "The Grapes of Wrath" by John Steinbeck. I think the reason most people get so uptight when I mention this book is because they were probably forced to read it for school. I had the privilege of reading the classic before it was assigned to me and it made all the difference. I would encourage everybody to revisit "Grapes", as well as any other piece of classic literature that may or may not have been ruined by unreasonable reading deadlines.