There was an amazing blog post (http://41latitude.com/post/2072504768/google-maps-label-read...) on 41Latitude when it still around about the absolute thing of beauty and art that is the labeling and visual design of Google Maps that enable it to have extremely high data density, while maintaining perhaps the best readability of any of the interactive maps out there. Correctness is the most glaring issue, but it's far, far more that sets Google apart from what Apple launched in their maps application.

EDIT: Here is an archived version found elsewhere: http://www.allhatter.com/showthread.php/13017-Google-Maps-am...