I also vote for taking a stroll down the main drag of Narita City. Visit the Naritasan Temple and eat grilled eel at the quaint little restaurants on that street. After that try some of the local sweets and do some sake tasting. It is not the hubbub of Tokyo, but a very relaxed outing of a quiet little Japanese town. I did that a month ago, and I was so glad that I did not rush to get to and back from Tokyo City proper.

Good luck.