Wild Bill's Bar & Grill
Beach rd, garapan, (http://www.wildbillsaipan.com). great omelets, hash browns, and pancakes.
Many nice bakeries exist in and around Garapan and local breakfast places are within walking distance of the main hotel area. Seafood is understandably very fresh.
Hard Rock Cafe, Tony Roma's, McDonald's, KFC, Pizza Hut, and Subway. Vegetarian options are possible to find as well. For self-catering options, try one of the Joeten supermarkets for fruits and vegetables, some locally grown.