I'm kinda fascinated with the way a story is transmuted from one form of storytelling to another; in how books like the Lord of the Rings or Pride and Prejudice, for example, change as they become films or minseries, musicals or radio plays etc. (Earlier post on this phenomenon re: Atonement.)
The latest such translation I've seen are the mysteries of author and forensic anthropologist Kathy Reichs. After enjoying the TV show Bones, loosely based on her life and writing, I decided to read her first mystery Deja' Death. One book is not enough to judge from, but I have noticed a few things: the TV show, being a visual medium, emphasizes the "Ick!" factor of seeing the body-of-the-week, while the book emphasizes the deep cruelty and perversity of its crimes in a way the show skims over; the TV series is an ensemble piece, while this book at least, is a loner's story; and the book's main character, Dr. Temperance Brennan, is a pretty normal person with caught-in-a-thriller problems, but the Temperance of the TV series is more damaged, frozen emotionally by the circumstances of her upbringing... which adds a great deal of depth and room for character development.
So far I like the TV show better, mostly because of the secondary characters, but I'll definitely be reading a few more of the books.