Asklemmy

Hunger games.

Well. It's clearly not a book, but Disney's Hercules was the first time I really felt disappointed about going to the cinema. My ten year old brain was having none of it. I wanted the adultery, the murder, the dirty stuff the story was supposed to have and I think it's the Disney film (that I've watched) I hate the most up to date.

I'm sure it's not the worst but I felt like the adaptation of Watership Down changed the tone/message compared to the book. Now granted the infamous violence is present in the book (though seeing it is more visceral than reading about it). But in the book there's a nice story at the end where Hazel is injured (iirc) and is taken in by a little girl and her parents who take care of him while he recovers before releasing him back to the wild (which only adds to his legend, of course).

Removing this bit, the only positive interaction with a human, makes the message feel more like, "Humans are bastards and inherently anethma to the natural world, which is also a brutal war of all against all even down to the cutest softest creatures." It just makes you feel bad, whereas the book might make you feel bad at times but it also offers an example of what you can do right. It's kind of a pet peeve when a work with environmentalist themes falls into that line of "Humans are the problem and there's nothing you can do but feel bad about it."

The Black Cauldron

The NeverEnding Story

Inkheart by Cornelia Funke is one of my most beloved series

read that series several times and when they announced a movie I was so hyped!

and the movie was just ok :C
I haven't seen any movies based on books since then unless it receives high praises which I haven't seen much

The two adaptations of Watchmen have both missed the point. The Zack Snyder movie treats the characters like gods rather than deeply flawed losers and weirdos.

The HBO series is better, and does get very close, but collapses from a meandering plot and glorifying cops

A Wrinkle In Time was fucking insulting.

I think it was much worse for people that actually liked the book.

Queen of the Damned was pretty awful and threw out the majority of the storyline.

Don't know if it counts as "classic", but Mortal Engines comes to mind. The film cut out over half the book. I loved the book and got really excited for the film, but it was a massive let-down. They could've easily made the film twice as long, maybe more.

The vampiers assistent, bases on the Darren Shan series. The tried to fit the first 3 books and the last one in one movie, and skipping over the other 8 books.... And who is Rebecca the monkey girl.... I wand Debbie and Sam....

I know its not a classic, but Dan Brown's inferno the book and the movie have two different endings and it angers me every time.