We just stayed a week in Tokyo - the first night we stayed in the Cerulean tower, which had a great view and is a very nice hotel, however it's a bit pricey compared to other hotels in the area. One nice thing is that there are shuttle buses that go direct from the airport to the hotel basement drop off point.
After our first night, we moved to the Granbell hotel, which is a great little boutique hotel just about 2 blocks away (5 min. walk). This one is a pretty decent hotel - we just got the cheapest room for 2 people - the room is pretty small, a bit smaller than the Cerulean, but since we were out running around all day it didn't bother us much. The bathroom was interesting as it was a glass enclosed area with a curtain to pull for privacy (note that the door was also glass and you could hear everything, so if you are squeamish about hearing toilet noises, turn up the music or something ;)).
Anyway, to sum up: Cerulean: Nice but expensive.
Granbell: Very good value as it's a nice hotel, fantastic location, and much less than the Cerulean.