Harvard is rated second best.

Rank University

1 Harvard University

2 University of Cambridge

3 University of Oxford

4 Massachusetts Institute of Technology

4 Yale University

6 Stanford University

7 California Institute of Technology

8 University of California at Berkeley

9 Imperial College London

10 Princeton University

According to Newsweek, 2006:

Rank University

1 Harvard University

2 Stanford University

3 Yale University

4 California Institute of Technology

5 University of California at Berkeley

6 University of Cambridge

7 Massachusetts Institute of Technology

8 University of Oxford

9 University of California at San Francisco

10 Columbia University

http://colleges.usnews.rankingsandreviews.com/usnews/edu/college/rankings/brief/t1natudoc_brief.php

2)Harvard

3)Yale

But thats in the US.