I've released an update to my detailed line-level map of the London Underground.
After some discussion with various people about the inconsistency of which details I had included, I decided instead to just include everything - thus, this new version includes depots, disused stations, sidings, crossovers, and most other track details (with a few omissions, noted on the map near the legend).
You can download a PNG or PDF copy, or read more on the project page.
I'm also considering getting some poster-size prints of the map done; contact me if you'd be interested in one.