A great lobster dinneri
In Philadelphia the first place that comes to mind is Oyster House. Definitely have it every day.
Devon Seafood, and the usual steak house suspects have lobster or lobster tail. Barclay Prime does a butter poached lobster.
If you want a chain in the KoP area.. Legal Seafood at KoP mall is passable.
You could go the Asian Route.. Budakhan has a spicy lobster dish. Perhaps others can suggest better options for other Asian style lobster dishes in Chinatown.
Route 6 is a new Starr seafood restaurant up by Osteria on Broad Street. It is just opening. I am sure it will have lobster.