For an intercity journey, Wolverhampton-Birmingham. The whole lot is grim.
It was much worse in years gone by, when there was an iron foundry right under the line at Crane St and huge gas works around Bilston.
In fact it's surprising how quickly the greenery has taken over in some areas, though there is still much dereliction.
I think it's time those black metal horses at the lineside were removed, myself.
I've no idea what they are supposed to represent, and there's one cluttering the platform at Wolverhampton.
Much the same applies between Longport and Kidsgrove - in fact it's a lot better than it was now the collieries, steelworks and pot banks have gone.
I find the old Trent & Mersey canal architecture at Kidsgrove fascinating, and the new (BR) Harecastle rail tunnel is much nicer and shorter than the old one, with the line now going through a park.
I find the run into Euston pretty grim, particularly about 2 miles out where blocks of flats back onto the railway.
Much the same into Liverpool St and most London approaches, which go on for miles and miles.
The elevated railways around Manchester city centre were also awful, but they have recently sprouted multiple tower blocks which has changed the scenery a lot.
However bad folk think our railway lineside view is, there are plenty of far worse examples on the continent where they have lost the plot with graffiti.
The approach to Paris Nord from the airport is especially bad, but also any big city in Italy will give horrific views on the approaches.
Even pristine Switzerland is not immune.
Then in some countries the train itself will be plastered in graffiti.
The Circumvesuviana in Naples is particularly repulsive.