The MBTA visualization[1] of the Boston subway system is phenomenal; a clear homage to Marey's trains[2], a beautiful train schedule graph from the late 1800's which I first came across in Edward Tufte's "The Visual Display of Quantitative Information".
[1] http://mbtaviz.github.io/
[2] http://www.edwardtufte.com/bboard/images/0003zP-18547/VDQI_P...