Sorry to be chiming in late here. I just saw this post. NRT can be a fun layover.

I stayed at the Hilton, which is probably the nicest hotel at NRT, but nothing special...the ANA would be fine too. I got a decent in-room massage for about $60 and hung out for a while before hitting the bars...

The bar at the Hilton is sort of fun with an American singer. We had the UA crew come by with some of them drinking until they were trashed (I hope they had a 48 hour layover)...they popped over from the hotel across the street where they were staying.

But, what you really NEED to do is go out at night into Narita to two airline crew hotspots:

1. The Barge Inn is the first stop, particularly because the second stop doesn't open until midnight or so;

2. Then, everyone hops over to the Truck Bar (literally situated in a truck).

All of this pre-supposes that you enjoy interacting with airline crews.

Otherwise, go into Tokyo, but it's a long trip in and out.