I think mine’s Z for Zachariah. The book is insane. A psychological survivalist thriller between a 14 year old girl and a strange man with unknown intent. The movie is… not this. They changed everything meaningful about the characters and lost all the tension. Hope someone does it properly one day. What’s your adaptation peeve?
The Count of Monte Cristo - Just cannot be adapted into a 2 hour movie. Many characters are completely cut out, relationships between characters are switched around, and the ending is different. It really needs to be a series to do the book any kind of justice.