Books that have really stuck with you, but haven’t been adapted into a film

I’m looking for book recommendations that had a profound affect on you throughout the years.

One stipulation is the book cannot have already been adapted into a film – I find it jarring and read the characters as the actor portrayed them. I’d prefer to let my imagination run as the author intended.

Having watched The Long Walk recently, I wish I had read the book beforehand (I probably will do in the future)