Roppongi is another great area with so much to see and do! Mori Tower is definitely a highlight. We went to the Modern Art Museum and then up top to the Sky Deck above the tower.
This has to be one of the highest points I've ever been to where you can view the skyline without a window blocking you. Also, this sky deck doesn't seem to be as busy as the other places available for sky view, I'm guessing because the Skytree boasts higher views and the Tokyo Tower is a major tourist attraction but I highly recommend the Mori Tower, you'll get an incredible skyline that includes Tokyo Tower!
We stayed up to watch the sunset again. I really love night views.