Could you tell me what is the healthiest food in your opinion?

For you?: Whatever you like best, but won't eat too much of, and isn't salt, sugary, or greasy. For me, it's probably oranges.

No one: singular "healthiest" food. Remember the healthiest diet involves variety too. Also be careful about focusing too much on soley "superfoods". While many of them - particularly bitter dark green leafy veggies(spinach, kale, swiss chard, dandelion greens) - are quite healthy, a you can find nutrient dense foods in a variety of forms.