The West Coast Mainline would be a good route. You have big stations such as London Euston, Crewe, Preston etc plus you got Carnforth which is also main base for West Coast Railway Company so you got steam and west coast diesels. You currently get Virgin Trains 390s pendalino, 221 voyagers, 4x Caledonia Sleepers that does the whole distance plus a large amount of Frieghts, auto train, MoD, Royal Mail EMUs and flask/nuclear waste. Also Crewe you get transport for Wales, Cross Country, Northern, East Midland Railway and London Northwestern Railway with near by Drs depots Preston you get Northern, Virgin Trains and Transpennie Express Glasgow Central you got ScotRail, Cross Country, Transpennine Express, Virgin Trains, London North Eastern and Caledonia Sleepers. Personally I would like to see a map that is from London Euston to Preston calling at Crewe.