The smart people at SF Signal took the NPR's list of reader-ranked top 100 books in these two genres, and turned it into a flow chart with 100 endpoints and 325 decision points. There is a printable version available here. (warning, huge download.) Not in the mood to follow arrows? There's an interactive online version here.
But for pure, colorful, joyful exploration of a cornucopia of best-loved books, take a few minutes to wander around this chart. Just keep an eye out for dragons.
(Click here to enjoy larger version.)