This set is the gold standard for early chapter books. It manages to be educational about STEM and civic duty without feeling like a dry textbook hidden in a trench coat. The characters have actual personalities, the art is stylish, and the message—that being curious is a superpower—is exactly what you want your kid to soak up.

If you've got a kid in first through third grade, just buy the box set and call it a day. It’s one of the few series that actually lives up to the hype and won't make you want to pull your hair out during the bedtime reading routine.