I've never been able to afford many coffeetable books. I adore the gorgeous photos, but the high price is pretty much unjustifiable. But the Net has opened up that world for armchair travellers. The photos of amazing places that I enjoyed in coffeetable books are now free online, shared by amateurs and professionals on sites like Flickr.
Wikimedia Commons has a page on World Heritage sites by country. If you have a few hours to spare...enjoy.