Which sub-Anorak route should I take?

1) Seeing ghost stations

The trouble with these is that apart from a few frontages, there isn't much to see really. You can't wander in a creep down into the bowels of the Earth like some latter-day Indy Jones to discover treasured possessions of the ancients, such as copies of the Times from 1942. Sadly. Unless you get into urban adventuring, and I'm far too wussy for that.

However, the Northern Heights looks good though - has all the requirements really - nice walk, bracing air, wrapped up warm, flasks of tea and stopping for some food somewhere.

2) Line-related station tour

a) The main ones here are the Charles Holden Piccadilly line extensions.
b) Holden's Northern Line extensions.
c) Central line into Essex.
d) Jubilee extension stations (have done before, but always nice)

Any tips?