It is your call if you want to believe this list, but here is a list of 129 foods claimed to be the World's Healthiest Foods. Actually, the list looks good in many respects. Each listed food has a link containing nutritional value and other considerations. The criteria to be named a most healthy food include (quoting from the site):
1. Most Nutrient Dense
2. Are Whole Foods
3. Are Familiar Foods
4. Are Readily Available
5. Are Affordable
6. Taste Good
Take a look.