HI Narita is just fine, especially as they put all room categories up for redemption so you can take the best they have (although this is an old hotel so not saying a huge amount!). It is the nearest to the airport, though, and has the most frequent evening shuttle service from Narita which will be important to you.

The basic rooms are very cheap for cash stays, though, so you may want to save your points unless you have loads or want a better room. I stayed on points in May but I am swimming in the things!