How would The Doctor's life look if it were mapped out as a subway map showing all the villians that the many incarnations of the Time Lord has come across as stops? This design by Crispian Jago (who previously put together a Tube Map of modern science) does a pretty darn good job of the whole thing. If you're looking for the most recent Doctors, light blue is David Tennant and orange is Matt Smith, but you really should look at the full thing at the link for a bigger view plus the color key to the corresponding Doctors.