I don't know if you want to leave the airport grounds, but not far outside the airport is Narita View hotel. They have a wonderful breakfast that includes a buffet of Japanese and American dishes. They also have a bus service every 10 minutes that goes to the hotel and back to the airport. We stayed there on our trip in May 04 and enjoyed the breakfast--don't know what time of day your layover is, but this may be an idea for you.
there is a shop in narita terminal 1 called arashi that serves a not-half-bad shoyu genkotsu ramen. if you can make it to the town of narita, there's one called ramen-tei that has an excellent shoyu ramen, but it's been a while so i'm not sure if that's still there.
I have two places I religously eat out depending on which terminal I am leaving from. From Terminal 2 there is a Thai shop up on the top floor of the restaurants complex. It is staffed by Thais and most of the customers appear to be airport employees and flight attendants.
In Terminal 1 (I hope I have these right) there is a tonkatsu shop. This time of year you can get kaki fry (oysters). It is on the top floor where all of the restaurants are. There is also a sushi shop nearby if you want your last fill of sushi. You can also take a box of sushi to go for your on-board meal.