If you guys are coming through Philly @ dinner time and want a Cheesesteak this is my reccomendation
http://www.tonylukes.com/stores/ion:
There's the iconic war of Pat's vs Geno's but this is a step above in my opinion as I've tasted each of them. They also have a Roasted Pork Sandwich which is very good as well.
If you get into Philly earlier there is also the Reading Terminal Market
http://www.readingterminalmarket.org/ They close @ 6:00 pm but in there is place in here called DiNic's very good Roast Beef and Roast Pork Sandwiches.