I go to Penn Station for the Grilled Artichoke -- I've never had a sub like that at a chain anywhere else. The fresh fries and lemonade are really good too. The place is always clean, and the staff is efficient and friendly. I've never had to wait long for an order, even a big one, and the complimentary newspapers and TV help pass the time.
When I last visited and was placing a big order, I did notice something a little strange: on their menu, it's less expensive to order two six inch sandwiches rather than one 12 inch sandwich. Just a tip, in case you're ordering in bulk.
My only complaint is that sometimes my food has come out a little greasy. Perhaps it's just too hot off the grill.