The axonometric, not-to-scale diagrams are pretty sweet — like the castings made of underground ant-colonies, cross with the insane arcology furutism of Paolo Soleri.
Ian Mansfield's taken the maps that Transport for London released and improved them, releasing them on his site:
"In total, some 120 stations are represented in this motherlode of tube and map geekery. I've removed the redacted black blobs that are scatted over the originals, and generally cleaned them up a bit."
3D maps of every Underground station – HIJKLM [Ian Mansfield/Ian Visits]