Harry Potter was a smash hit about a boy discovering he’s a wizard and going to school in a magical world full of wonder and adventure. Twilight didn’t hit quite that high a note, but the story of a teenage girl who learns her classmate is a vampire and falls in love with him did quite well. The Hunger Games popularized the dystopian genre with a bow wielding teenager stepping up to survive death games, have angsty romances, and fight the power.
As far as I can tell, nothing has quite hit that same kind of high since and it may be awhile until the next truly big wave. But if it were up to you, what would the next big thing be about?
Schoolmance series. 1st pretty good. It expands that the school has a will of it’s own, and safety diff. Not guaranteed. After that, not so much, but rewrites could fix that for TV or show adaptation. Red rising also comes to mind.