Strange Maps is a good blog to keep an eye on. Most of the maps on that blog are so ridiculous they are of interest only those people who have a fetish for maps (though as a web site that has its own map maybe we should not cast stones). But amongst the dross there are quite a few gems.
Also worth checking out is this map comparing the population of China’s various provinces to the population of various nations.
And last but not least is this map of genetic variation in Europe.