You've got to explain what route you want. From where to where, what trains, service pattern, map. I only know septa exists but I don't know anything about them. People will not be interested if you don't provide more information. Also responding again in all caps won't help either if you do not have a good suggestion that doesn't just say "I want this."
Trenton line from Trenton to Chestnut Hill East is a good line to appear imo. It can be also shortened so it goes as far as Philadelphia 30th Street.
Sherman Hill length service is R5 Doylestown Thorndale LGV 58 mi 93 km length is R2 Warminster Newark,DE.
There are plenty of other suggestions out there that are pretty good so you can have a look and edit your post so it's more informative.
I'd put Septa in unknown atm, the only TSC route that would of featured them is the ancient NEC route between New York and Philadelphia, and that inly came with the AEM-7 and no unbranded Septa stuff, so we really can't judge atm if they are in licensing hell or not.