Addiction by Design, A Language Older Than Words, WTF?!, Blowback, The Sun Is a Compass, So Good They Can't Ignore You, Sophie's World, Sandman 4, American Gods, Letters to a Young Mormon, +2 more!
I did read "Sophie's World" when I was in high school, and I thought it wasn't so interesting. In particular, I didn't get the metafictional ending at all - I understood it, but it seemed put-on and unwarranted.
I don't remember much of what I thought about the rest of the book, so I probably assimilated it into the gestalt of my history-of-philosophy knowledge without much more.