If you live in or near Chinatown, NYU Palladium, University Hall, Gramercy (23rd St and 3rd Ave), University Court (25th St and 2nd Ave), or NYU Langone Medical Center (34th St and 1st Ave), then take the ‘free‘ NYU bus to get to campus. The following link will allow you to get the schedule, which is runs on three schedules: Monday-Thursday, Friday, and Weekends: http://www.nyu.edu/public.safety/transportation/routes.html.
If you have an iPhone, download the transloc app so you have up-to-date real time information on where the buses are!