Which public transportation ticket would you recommend (cheap and with unlimited rides within the City of New York, especially Manhattan) for two guys who want to visit NYC only (no suburbs) this summer. The stay in NYC is about 5 days (Wednesday till Sunday). We both are students from Germany and are equipped with both international student ID and student ID of our home university in Munich. Are there some discounts for students like us?
I was there last month, and while there's no additional student discount, every traveller (pretty much) in the hostel used a 7 day Metro Card, for $30 (plus a $1 activation fee for the card).
This and other options (hop-on/hop-off bus) for you to look at are available on the relevant NYC Transportation page.
It was honestly the most convenient option. The subway goes almost anywhere you could possibly want to go as a tourist in that time (I also stayed five days), and considering the price of a single journey, it's well worth getting.