[everybest]

I would get a rail pass since it works for both the JR and the metro and you won't have to worry about where you're headed and buying the right amount ticket, or even buying a ticket each time you want to take the metro/JR. On a busy day, I use about 600 yen and to get a pass, i think the minimum is 2000 or so and you can recharge it anytime. Since you're gonna be there 2 weeks, I would pick one up, it makes traveling so much more convenient and with Tokyo so crowded, this should save you some unnecessary headaches.