Watching the sunset from Roppongi Hills was my favorite Tokyo experience. We bought tickets to the Mori Art Museum, which included entrance to the observation deck on the 52nd floor of Mori Tower. We payed 1500 yen ($17) for the museum and observation deck and an extra 500 yen ($5.69) to go up to the open-air sky deck. The sky deck is literally on the roof of Mori Tower and has a completely unobstructed view of Tokyo Tower, Rainbow Bridge, and the sprawl of Tokyo with a helicopter pad in the center. We saw the Aida Makoto exhibit at the museum, an entertaining modern exhibit made even more exciting when we got to the end and saw the artist working on his pieces. From of my four-day stay in Tokyo, this is my number-one recommendation.