I think that a great route to see in Train Simulator would be a Thameslink route. My proposal is the route from Sutton in South London to St Albans City, just north of London. This would feature 31 stations and look like the below map. This route would go both directions in the Sutton loop, both via Mitcham Junction and Wimbledon. This route would be driven with the class 700 dual voltage EMU and would provide a variety of services from the third rail in south London to the overhead wires in north London, meaning that the pantograph has to be raised/lowered in the core section. This route may also feature ATO in the core section, but I do not know if Dovetail can replicate that. This would also feature London Blackfriars station which is located on the River Thames. This route is approximately 43 miles in length, which I think is a reasonable length as it is only 3 miles more than LIRR.