14 days JR pass + suica or pasmo

Hi! I will stay in JP 15 days and I have bought the JR pass for 14 days. I will arrive in Tokyo and activate immediately my jr pass to reach tokyo shinjuku by train. I will spend 3 days in tokyo trying to use JR lines to visit the city and I will be back to tokyo the last two days of my vacation. the last day I will take the train from Shinjuku to narita. My question is, for the extra day and for the days I will spend in tokyo it is better if I purchase a suica or pasmo card to take subway and the train to narita the last day or it is better if I purchase the daily ticket?? Let me know.. I am not sure I can maximise the use of my JR pass while in Tokyo. The Yamanote Line and the chuo line seems to be ok but they don't take you everywhere.. wait for your advice. tks

Buy the one way Suica + NEX package when you arrive and use it to get into Shinjuku on Day 1.
http://www.japan-guide.com/e/e2359_suica_nex.html

The Suica + NEX package gives a big discount on the NEX so is well worthwhile given your schedule.

Set the activation date of your JR Pass as Day 2 so that it is active on Day 15 to get back to the airport.

You can then use the Suica if you wish to use the subways, or the JR Pass from Day 2 onwards if you wish to use the JR Lines.

At the end the JR Pass will cover the NEX back to the airport, just don't forget to reserve your seat.

Enjoy your trip!