Artemis Fowl

Irish author Eoin Colfer published Artemis Fowl on 26 April 2001, pitching it with a line that did all the marketing on its own: "'Die Hard' with fairies." The premise inverted every children's-fantasy rule of the Harry Potter boom. Its hero was the villain — Artemis Fowl II, a twelve-year-old genius rebuilding his family's criminal fortune — and its fairies weren't twinkly garden sprites but a high-tech underground civilization with its own police force and serious firepower. Artemis kidnaps Captain Holly Short of the LEPrecon fairy police and ransoms her for gold, and the book plays the siege that follows as a heist thriller that happens to star middle schoolers and magical creatures.

Kids devoured it. Eight books followed through The Last Guardian in 2012, tracing Artemis's slow, grudging drift from villain to something like a hero, and by 2013 the series had sold more than 21 million copies in 44 languages. In 2010, readers voted the first book their favorite Puffin title of all time — over some historically stiff competition. It became a fixture of book fairs, summer reading lists, and the backpack of every kid who liked their fantasy with schematics and sarcasm.

The long-promised movie became a cautionary tale instead: Disney's 2020 adaptation, dumped to streaming after years of development, was savaged by critics and fans for gutting the character's villainy — accidentally proving the books' whole point. The boy genius only works when he's allowed to be bad.