4. Literally everything by Tamora Pierce
Why they should be movies: Tamora Pierce is the OG "strong female protagonist on an epic adventure" writer. While all of her series would make fantastic films, the Trickster books are the most substantial, not to mention there is a great opportunity for diverse castings with the multiracial princesses Saraiyu and Dovesary.
Will they be movies?: Probably not, since Pierce has argued that her books all take place in the same universe and would have to be made under the same studio.
6. The Subtle Knife and The Amber Spyglass by Philip Pullman
Why they should be movies: So they tried to make The Golden Compass happen and it didn't quite work, but His Dark Materials gets much better. Maybe the studios just need some encouragement to keep going: Come on, little buddies, you can do it! Get back on that polar bear and ride it to victory!
Will it be a movie?: Seeing as most of the child actors have aged out, it's unlikely that we'll see The Subtle Knife or The Amber Spyglass anytime soon.