Another location for the school project... Shibuya! Actually one of my favorite places in Tokyo: close to my house, lots of food (!), and high energy. Did I mention they have a Starbucks?
Shibuya is known for it's huge cross walk outside the station. You take Hachiko Exit from the station. Once the lights change in favor of the pedestrians, people walk in three directions at once-- all motor traffic is stopped! There are mobs of people in a near-constant flow, which I like to watch from the 2nd floor of the Starbucks!
There are also a lot of signs/advertisements on the walls of the buildings. Several huge television screens blare music and light unto the intersection.