If you're in the Tokyo area, take the Yurikamome line down from Shimbashi station and you'll find yourself on the lovely man-made island of Odaiba. If you like sightseeing and shopping, then I'd highly recommend checking this place out. Odaiba is one of the most popular shopping and sightseeing destinations for locals and tourists alike. You can pretty much spend most of the day checking out all the nifty little attractions that this place has to offer, such as Miraikan, Aqua City, Diver City (where the giant Gundam Wing statue is), the Statue of Liberty replica, and Palette Town.
Most of our time was spent either eating, shopping, or going to the wonderful arcades. This is one of those times where you wish you spoke and read Japanese, because it really limited us to what we could have done. Regardless, we had a great time seeing the sights and visiting this place.