Morton's Steakhouse located downtown. Yes it's a chain restaurant but the cajun ribeye is excellent.
Champ's in Bensalem is not very far from downtown. If you go to Champ's ask for the special cheese steak. It's your typical Philly cheese steak, but its with topped with pepperoni, mushrooms, pizza sauce, american and provolone cheese. One the best sandwiches you will ever eat.
Ashburner Inn has a damn good seafood bisque.
http://www.ashburnerinn.com/menu/menu.html