I noticed two major naming trends while putting together my list: first were books named after a primary character or institution within the story; second were thematically significant words. In this case I personally prefer thematic titles that add to your appreciation and understanding of a book after reading!
Featured in the header, and chosen because it pulls triple duty as the protagonist’s surname, a thematically important word for the story, and a thematically appropriate word for this post: Less, Andrew Sean Greer.
Misery, Stephen King
Wit, Margaret Edson
Ceremony, Leslie Marmon Silko
Sadie, Courtney Summers
Rebecca, Daphne du Maurier
Circe, Madeline Miller
Deathless, Catherynne M. Valente
Soundless, Richelle Mead
Warcross, Marie Lu
What single-word titles are on your bookshelves?