Tokyo Metropolitan Government Building
Aside from being the headquarters for the Tokyo Government, the 45th floor of the main government building are the "South Observation Room" and "North Observation Room". This is where you can enjoy the city of Tokyo from a height of 202 meters*. When the weather is nice, you can see famous landmarks such as Tokyo Dome, Tokyo Sky Tree, and even Mt. Fuji.
*Currently, only the "South Observation Room" of the Tokyo Metropolitan Government Twin Tower is available. The North Observatory is currently closed and will be re-opend around mid-January 2020.