Would love to see another Glasgow suburban route. The North Clyde routes give so much scope for varied timetables, train types and future expansion. Milngavie to Edinburgh and Springburn perhaps? Good rolling stock options too. Class 334, with 320 as DLC for North Clyde and Cathcart circle would be ideal.
The North Clyde Line is a great route which hopefully we will see in the future. I think you could get away with Helensburgh/Balloch - Springburn/Airdrie for the full 'urban' section around Glasgow & Clyde, I have suggested this before and so have others, so good to see it still has some support out there.
Balloch/Helensburgh would give some good scenario options too using the different lines towards singer or Clydebank, as well as some nice scenery heading down the Clyde coast to Helensburgh