Tried to go 'outside the box' here, rather than lean on old standby favorites...
15th - Favorite Agatha Christie mystery
16th - Favorite picture book
17th- Favorite literary detective
18th- Favorite seafaring novel
EDIT- I'm going to blame the horrible colors in the image I printed out of the list...
#18 should be #19 and #18 should be favorite coming-of-age novel... which my choice is Roll of Thunder, Hear my Cry by Mildred D. Taylor.