A neat article on Underground Typography compares the navigation of three major subway systems: London, New York, and Paris. I've ridden all three systems (though not London in ages) and I love that Paris and London tell you when the next train is due. Both those systems exhibit an orderliness that's apparent on the streets above. And the Paris metro font is amazing. But New York's subway, for all its grime and confusion, is my favorite because it's the embodiment of the city it serves: diverse, fast-paced, surprising, confusing, and awe-inspiring when you think of how it actually all works.