It has become a tradition to go to Paula's Cafe while I'm visiting in North Dakota. Paula's is located in Mayville, North Dakota and I can't say enough good things about this restaurant! It's charming; in a simple, understated manner.
The Washington Post has a great article "Following Steinbeck to Fargo" by Rachel Dry that is completely read worthy. Not only does she describe her visits to Rugby and Fargo, North Dakota, but also her side-tracked stop to Mayville, where she dined at, none other than, Paula's Cafe.