Check out Cameron Booth's depiction of the NYC Subway map in the style of the London Tube map. He managed to finish it despite some fundamental differences between the two underground systems. The NYC Subway is infinitely more complex in transfers and station layout than the London Tube (not to mention bigger as well) so Cameron had some challenges to tackle in terms of labeling transfer points and noting regular service changes depending on the time of day.
There is a lot of information that isn't shown on Cameron's version, but as a piece of art, it is quite nice from a distance. Just don't rely on it for any actual relevant travel information.