Your best bet is to look at universities with strong public health schools. These will always have more opportunities to get involved in public health and take public health electives. There are also a few schools that don't have public health schools, but are known for emphasis on public/global health and have global/public health tracks.
Off the top of my head, and in no particular order, some examples are:
- Harvard
- Johns Hopkins
- Yale
- University of Washington
- University of North Carolina - Chapel Hill
- University of Michigan
- Columbia
- Emory
- University of Pittsburgh
- Boston University
- Duke University (no public health school, but you can get a Master's in Global Health in the 4 years)
- Cornell (no public health school, strong global health emphasis)
- Mount Sinai (no public health school, strong global health emphasis)
- George Washington (global health track)
- Dartmouth (global health scholars program)
- Stanford (no public health school, but can get funding to do MPH at UC Berkeley)
This is not an exhaustive list, but probably includes many of the best programs for public health. MANY medical schools now have public or global health tracks, and if you take a year off to do an MPH, you can do that MPH anywhere -- i.e. you don't have to complete an MPH at the same school you get your MD from.