Here's a random collection of titles:
The Martian Chronicles (Ray Bradbury)
Maus (Graphic novel about the Holocaust; won a Pulitzer. Art Spiegelman)
The Terrible Hours (Peter Maas; about a submarine rescue)
Last Chance to See (Douglas Adams goes off on adventures in search of endangered animals)
The Crowfield Curse (Historical Fantasy; Pat Walsh)
I've never been much of a devotee of Lexile levels or AR scores; I guess I don't like the idea of turning a work of literature into something with a quantifiable score. I suppose they work for industrial chapter books, but for real books...well, hmm.
YMMV, but I believe that reading and enjoying a substantial work with a plot and/or a theme is more important to brain development than aiming for something with an artificial score.
Please don't think I'm accusing anyone of anything here. My comment was more a dig at edumacator ideas regarding the merits of forcing kids to read books in a certain score range. Seems like...industrial schooling to me.
I'm just throwing out titles that may not hit the 7+ category in those systems. But all these books have consistent themes and ideas that can fire the imagination and get someone thinking about stuff.
Val
