Here are some good routes I found:
"Quahog Sub": A route based on SoCal but is very fictional.
"Baldwin Park": More of a railfanning route rather than a full-blown route based on a town in SoCal.
"BNSF Central Valley Subdivison": One of my personal favorites. A route that takes place in the...
Their is a guy named "maxwerks" on the DLS who made the "Stockton Subdivisions" route. He made a route called Modesto & Empire. I own the route. (WARNING: The route is pretty outdated with a bunch of old Trainz 12 stuff, so you will have to replace with more modern stuff if you want.)