The best hoagies that I've ever tasted came from Hatboro Market and Deli, not far from the Willow Grove exit off the Turnpike.
The rolls are fresh and hearty. And they pack them full of meat, cheese, lettuce and probably whatever else you request. Everything is extremely fresh and well made. While my favorite hoagie is turkey, I thought that I should also mention that their American hoagies cost only 99 cents, which is unreal for what you get in return. That's by far the cheapest price I've seen for a good size hoagie.
Besides the hoagies, they seem to have a very good overall meat selection. The deli alone is worth checking it out.