The Southern ManTM Site Of The DayTM is GraphJam, which is chock full of humorous graphs and pie charts and Venn diagrams and such. Here's an example that hits rather close to home right now...
Many of these will test your knowledge of pop culture and song lyrics (or, in Southern Man's case, reveal his lack of such). In other words, you either get this one or you don't:
Not to worry: there are "cheat sheets" (mostly "cheat videos from YouTube") for most of the graphs (and a good deal of the pleasure of this site is clicking on those). But the wisdom of Yoda is known to all:
so Southern Man sez go browse around and see which ones strike your fancy!