Sliding Scale of Book to Movie Adaptations

There are quite a few factors when grading a book to movie adaptation. This is how I categorize them when putting them in context to other people (readers or non-readers of the book)

Here is my scale:

Category A: 

• Adaptation is in the 90-100% accuracy range, fans of the book are happy, can be watched whether you have read the book or not, could inspire people who liked the movie to read more of the author as well as the book
• Examples in this category: 
• A&E/BBC's Pride and Prejudice
• The Girl with the Dragon Tattoo (American)
• To Kill a Mockingbird
• The Godfather
• Atonement
• Shutter Island
• Persuasion

Category B:

• Adaptation is in the 75-89% accuracy range, fans are reasonably happy, but argue about choices, stands well on its own for non-readers, fans of the film would consider reading the book
•  Examples in this category:
• Perks of Being A Wall Flower
• Ender's Game
• Fight Club
• Lord of the Rings (All 3 books)
• Time Traveler's Wife
• Gone With the Wind
• Stardust
• Sense and Sensibility
• Rebecca

Category C:

• Adaptation is in the 55-74% accuracy range, fans of the book are split 50/50 with their love of the movie, non-readers like if not love the movie version despite that, there is no guarantee anyone who watches the movie will ever read the book
• Examples in this category:
• The Shining
• The Great Gatsby
• Bridget Jones Diary
• The Hobbit (All parts)

Category D:

• Adaptation is in the 40-54% accuracy range, fans of the book tend to dislike the movie with few exceptions, non-readers don't necessarily get everything that is going on, but the movie is good enough to enjoy, non-readers won't want to pick up the book at all
•  Examples in this category:
• Percy Jackson and the Sea of Monsters
• Water for Elephants
• Eat, Pray, Love
• Hunger Games/Catching Fire
• Hitchhiker's Guide to the Galaxy

Category E: [Difference between Category E & F is non-reader's reaction]

• Adaption is in the 1-39% accurate range, fans of the book are down right angry about it, non-readers rather enjoy the movie as it can stand on its own, non-readers want to read the book, but end up either not liking it or just as angry as the fans with the adaptions levels
•  Examples in this category:
• World War Z
• Where the Wild Things Are
• Dexter (TV series)
• V for Vendetta

Category F: [Difference between Category E & F is non-reader's reaction]

• Adaption is in the 1-39% accurate range, fans of the book are down right angry about it, non-readers don't like the movie because it is either poorly made or too confusing to follow, non-readers don't even know or care there was a book
• Examples in this category:
• Percy Jackson and the Lightning Thief
• Watchmen

My examples are ones off the top of my head for each category and is meant to illustrate my criteria.