Akershus is perfect to meet princesses so if that is important to your kids go with Akershus. I happen to like the food there too because they serve the American style plates of eggs and stuff, but then they have a buffet of other food including some Norwegian favorites like gjetost cheese and smoked fish and fresh fruit.
Garden Grill gives you bigger plates of food and more variety at the table, plus country style Mickey and friends.
Both are good choices and depending on what you want to do after breakfast, they are both conveniently located near popular rides.