The summarized list of universities according to the number of Nobel Prize winners (unergraduate degree only):
Harvard University: 21
Columbia University: 16
University of Chicago: 13
Massachusetts Institute of Technology: 11
University of California-Berkeley: 11
Yale University: 11
California Institute of Technology: 8
Cornell University: 5
Swarthmore College: 5
University of California-Los Angeles: 5
University of Illinois-Urbana Champaign: 5
University of Michigan-Ann Arbor: 5
Amherst College: 4
Carnegie Mellon University: 3
Case Western Reserve University: 3
Dartmouth College: 3
Princeton University: 3
University of Pennsylvania: 3
University of Rochester: 3
University of Washington: 3
University of Wisconsin-Madison 3
Brandeis University: 2
Haverford College: 2
Johns Hopkins University: 2
Oberlin College: 2
Purdue University-West Lafayette: 2
Rice University: 2
Rutgers University: 2
Stanford University: 2
University of Minnesota-Twin Cities: 2
Williams College: 2
Brown University: 1
College of the Holy Cross: 1
Georgia Institute of Technology: 1
Grinnell College: 1
Hamilton College: 1
Michigan state University: 1
New York University: 1
Northwestern University: 1
Ohio State University: 1
United States Naval Academy: 1
University of California-Riverside: 1
University of California-San Diego: 1
University of California-Santa Barbara: 1
University of North Carolina-Chapel Hill: 1
University of Texas-Austin: 1
Vanderbilt University: 1