Someone took NPR's top 100 science fiction and fantasy books and turned it into a flow-chart (http://www.sfsignal.com/archives/2011/09/flowchart-for-navigating-nprs-top-100-sff-books/). Go there for a printable or even an interactive version.
(http://www.box.net/shared/static/a6omcl2la0ivlxsn3o8m.jpg)
The interactive chart is pretty shiny!