The arun valley line between Pulborough and Ford has some very lovely scenary
What better than to sit on a leading end of a 377 with comfy seats and cool air conditioning while looking at quintessential English countryside ... just beautiful the way the track follows the river with glimpses of arundel castle and cathedral... wildfowl etc
a much needed green oasis in the built up south
yet because it is a commuter line it seems under appreciated
any others worthy of mention that are not obviously known?
There is a small section between Stockport and Manchester which I like, the mile just north of Stockport station, where the line goes over a high bridge and there are good views along the M60 towards the Pennines.
Sections of the Carstairs and Bathgate lines are surprisingly enjoyable.
Blackburn - Colne
Bridlington to Scarborough, Sea views leaving Bridlington, open views over the Wolds after Bempton, typical country views around Filey and Seamer, Olivers Mount as you wind into Scarborough. A lot of variation in a short distance.
York - Malton, specifically near Malton, where the railway follows the River Derwent, views of the ruins of Kirkham Abbey, and very little habitation in the steep sided wooded valley. You often see deer here, and the occasional buzzard.
The uckfield line would be smashing but it needs a hell of a lot of vegetation to be trimmed.
Around Eridge it would be "Picture postcard" stuff.
Barnstaple and Gunnislake tend to be forgotten down in the West Country.
I'd also put forward Stirling-Perth and the Tyne Valley.