This is 100% the litmus test I used before dating someone. If they hadn't read/hadn't heard of it, they were not for me. Heard but not read, it would depend on their willingness to read it with me.
Heard, read, loved - definitely long-term option. :D

What made that your favorite? I was a Laura Ingalls Wilder kid - I didn't read AoGG until we did it on the podcast, so I'm always interested.