There have been a lot that don't seem to have much added content, haven't there? This post had comments that included both lists of people's comfort reads and suggestions as to what makes that type of book, so the comment section was worth delving into.

A lot of Terry Pratchett -- but not all of it -- can fill that spot for me. I am ashamed to admit I haven't yet read snuff -- perhaps that's what I'll buy for the plane!