Depends on what grade you are specifically looking for.. NY Magazine provided a great analysis and list of public high schools in NYC that were great. It also included admission information, graduation rates, diversity rates, benefits, and downsides. The link: http://nymag.com/urban/articles/schools01/school3.htm.
There are also some other spectacular educational websites that you might find handy including some that have been mentioned before
This site gives rankings for elementary, middle, and high schools:
This site provides you a list of all the elementary, middle, and high schools in NYC, respectively. You can find out more about the school, how it fares when competing against other schools, ranking information by clicking on the particular school you are interested in:
And of course there is the staple website that many Realtors here on this site love: http://www.greatschools.net.
Sorry for the late response but hope this information helps.