Cape Cod/Nantucket Recomendations

[mike62]

Will be taking a day trip to both Cape Cod and Nantucket, looking for recomendations. Would really like to find a good lobster/lobster roll and some chowder for lunch and some thing different for dinner. Not going to pin it down to one style food, and not looking for any place fancy. Just a cool place to get some good food, bonus points for a great friendly atmosphere.