We recently started reading the Magic Tree House books. My daughter seems to enjoy them, although it's in pretty tough competition as we are 8 books in to the Boxcar Children series this year as well. ;) The great part about the Magic Tree House books is that she is able to do a monthly free online book club with them, and we've been putting together lapbooks as well.
Of course she loves making lapbooks. In addition, she is really liking the video of her teacher and can answer all the questions on the book; great follow-up for comprehension and further subject details with little effort on my end. We're still continuing with various Sonlight read-alouds and other study guides in Charlotte Mason style, but these books are a quick addition, we can read one in an afternoon if we want, and the Homeschool Share has free materials to pair with it, along with the Currclick online book club. Gotta love Currclick!!