A simple crowd pleaser: Superhero books!
Boys eat these books up. And, you may or may not be surprised, a lot of girls do, too.
I’ve only provided the publisher’s synopsis below, but mark my word, these books feature the classic characters and their usual good-guy-bad-guy anecdotes. I love that Wonder Woman makes an appearance. Some of the books have been made into level 2 readers for the kids that are gaining confidence with independent reading (some help may be needed). Putting a superhero book into the hands of a beginner reader is a great way to nudge them into the early-fluent reading stage—especially when you build them their own personal bat cave to read in (bat cave à la pillows and blankets). Holy books, Batman!