If you really care...
(averaged from the last five years of US News research rankings, as arbitrary as they are, rankings in parentheses and average at the end):
1. Harvard (1, 1, 1, 1, 1) - 1.0
2. Stanford (4, 2, 2, 2, 2) - 2.4
3. Johns Hopkins (2, 3, 3, 3, 3) - 2.8
4. Penn (2, 4, 4, 5, 3) - 3.6
5. UCSF (5, 4, 4, 3, 3) - 3.8
6. WashU (6, 6, 6, 6, 6) - 6.0
7. Yale (7, 7, 7, 7, 8) - 7.2
8. Columbia (8, 8, 8, 8, 7) - 7.8
9. Duke (9, 8, 8, 8, 8) - 8.2
10. Pritzker (10, 8, 8, 10, 11) - 9.4
10. Michigan (10, 8, 8, 10, 11) - 9.4
12. UWashington (10, 12, 12, 10, 8) - 10.4
13. UCLA (13, 13, 13, 13, 14) - 13.2
14. Vanderbilt (14, 14, 15, 14, 15) - 14.4
15. Pittsburgh (15, 16, 17, 16, 16) - 16.0
15. UCSD (16, 15, 14, 17, 18) - 16.0
17. Weill Cornell (16, 16, 15, 18, 18) - 116.6
18. NYU (24, 21, 19, 14, 11) - 17.8
19. Northwestern (19, 18, 18, 19, 17) - 18.2
20. Mt. Sinai (18, 18, 19, 20, 21) - 19.2
Caveats:
1. Regarding Harvard's stronghold on #1, the real reason why it is so high is because based off USNews metrics, it has an absurd amount of affiliate hospitals and institutions making it impossible for its amount of research funding to not secure it's #1 ranking. (See:
https://anastomosed.wordpress.com/2013/03/14/what-would-it-take-to-knock-harvard-med-off-1-in-usnwr/)
2. Interestingly, Stanford was barely in the top ten for rankings prior to the 2010s and I'm not sure why it's skyrocketed to #2.
3. These are all arbitrary and you'll get a fantastic education anywhere in the Top 10 or Top 20 so it's really more important to look at what your personal preferences are.
4. It is interesting to see what NYU's ranking will be in the coming years. For several reasons, like stat whoring, prestige whoring, receiving Hurricane Sandy funds, having a new Dean that is bringing in better faculty/grants, it has jumped from like #34 to #11 in the past decade.