Thank you all for your input and great feedback, after reading all this responses here is what I can conclude,
If you can get along with just 16GB of data then 16GB iPhone is best value, if you need anything more than 16GB dont hesitate buying 64GB version as that is next best bang for your buck. 32GB is goo compromise but you are leaving too much money on table in that case. Think it this way
$200 buys u 16GB of device,
if you pay extra $100 it buys you extra 16GB of data (takes to 32GB)
if you pay extra $200 it buys you extra 48GB of data (takes to 64GB)
so if you can survive on 16GB that is best thing, if not go for 64GB. Dont just throw away your money on Steve's shrine - he has lot of it.
. Think of it this way you are in negotiation with Apple, you show money they show you storage. At the end you want to make sure you can squeeze out most amount of storage for least amount of money and 64GB fits that bill if you cannot survive on 16GB storage.