@UWfromCA this aggregate ranking you mention blends rankings that measure both undergrad strength/quality and overall research & grad quality. this is not necessarily a bad thing, but it measures a blend of both undergrad & grad/research quality. UniRanks ranking focuses on research strength and the WashPo raking focuses on undergrad strength.
Also at the WashPo ranking the top 3 are Stanford/Harvard/MIT so yeah there is not much contention about the top 3.
WashPo Top 15:
1.Stanford University
2.Harvard University
3.Massachusetts Institute of Technology
4.Princeton University
5.Yale University
6.University of Pennsylvania
7.Duke University
8.Columbia University
9.University of California at Berkeley
10.California Institute of Technology
11.University of Michigan at Ann Arbor
12.University of California at Los Angeles
13.Rice University
14.Dartmouth College
15.Brown University