Whether you are writing a fantasy, action-adventure, mystery, growing up, or humor middle grade story, there usually is an element of danger in the plot line. It may be physical danger (The Book Thief, any of the HP books, Percy Jackson series), the threat of danger (Neil Gaiman's The Graveyard Book and the man who pursues Bod), or a fear that has become a danger in the main character's mind (any of the Diary of a Wimpy Kid books). Danger always exists.
It is a key element in pushing the main character toward the resolution of their conflict. There has to be some sort of motivation for the character to get through to the end. If there isn't, well, there really isn't a story. Just a bunch of words strung together that somehow was published!
We may as writers (or even as readers) not think of conflict resolution as the resolution of danger, but in most cases it is.
What are your favorite books that have danger as part of them?