The secret is the cheese. New York (really Staten Island) cheesecake uses cream cheese. This makes it sweet and creamy, and objectively the best kind of cheesecake. Italian cheesecake uses ricotta, and is hardly classifiable as cheesecake. It can be identified by its crumbliness, slightly bitter taste, and the fact that after making it you will feel an overwhelming since of guilt for tainting the cheesecake name.