I think that a great route to see in Train Sim World 2 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.
It would be good as well to have the Class 319 on this route as well. I'd definitely buy this route as it goes through my home town of Sutton
They could have it set in 2015-2017 where the 319s were being removed from service and the 700s were being introduced.