For some reason, I really enjoy Odaiba. Probably mostly due to the lovely monorail ride (which is horrifically overpriced... like 320Y one way) where you see lots of bridges, which reminds me of Portland.
Then once you get to the island, most of the buildings are really futuristic (see Fuji TV)- there is a lot of super cool architecture here. I have realized that I really appreciate Architecture; supreme in art and in function, and I seem to like combinations of that sort.
There is a large "promenade" type area near the bay... really pretty. I think this qualifies as another Tokyo Utopia...
Here's a couple funny-cool buildings... I don't know what they are called. And a strange rocket-shaped sculpture.