Student:
America's Best Architecture & Design Schools 2010
This link and $39.95 will get you the Design Intelligence 11th Annual America's Best Architecture and Design Schools.
And, contrary to your assertion, Cooper Union is not in the top 20. It is, however, listed as a "hidden gem of architecture education."
Rankings are worth only what you make of them. DI's listing, Archiecture Magazine's listing, even Archsoc.com's are all compiled based on the criteria that that individual list writer has decided is important. Whatever importance that criteria is to you is for you to decide. Your link, if you read the introduction, makes no pretense at being anything other than a summation of research - not education, not quality, not value, just "Our survey is intended to aid postgrads {graduates} seeking a place to conduct architectural research."