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?
Eragon. It wasn’t even a decent movie. They skipped so much and it was such garbage. I loved the books as a teen, and was excited for the movie. But god that movie was trash.