Nationwide Pass or East Pass

Hi,
A JR East Pass would be a big waste for your itinerary. If you get a 7 day full JR Pass, activate it at Narita and use it for the Narita Express into Tokyo and then go to Kyoto and back to Tokyo with it, you would recoup the cost. Spending at least half a day to see Nara near Kyoto is also well worth it. Any other available days on your pass could be used within Tokyo on the JR Yamanote Line, which goes to many popular tourist areas.
One of the most popular places to see in Tokyo is the Sensoji Temple. Seeing the Tsukiji Fish Market at the crack of dawn is also something you will never forget. Harajuku on a Sunday afternoon is the best time to see the youth with the wild fashions, and the walk through Meiji Shrine and Yoyogi Park next to it is quite relaxing.

Good luck.