Government building
This is the really tall government building in Tokyo. It's a whopper, and aesthetically pleasing too. You can go inside to the north or south towers, where there are observation decks. Up there you have an excellent view of the city, and the souvenir shop. Don't bother with the restaurant at night. Unfortunately they had the rather stupid idea of putting very well lit greek columns all around the centre, so that the diners lucky enough to sit near the windows can't see out due to the bright reflections... I think that this was the only time we have come across bad planning in Japan. All in, they think of nearly everything (just not night observation conditions).