(Caveat: That assumes that you are an average person with an average metabolism. There is a portion of the population that cannot survive on a vegetarian diet, for such people adding eggs or meat will help tremendously.)
After those three, I'd suggest tomatoes, potatoes, and some kind of greens.
Personally, I'd also grow beets, cucumbers, melons, amaranth, millet, sunflower, wheat, herbs, and a whole slew of berry bushes. And I'd also make sure there were enough extras to keep a small rabbit colony, because I know for a fact that I'm missing the enzymes needed to obtain protein from vegetable sources.
Working on expanding my garden so I can do all that.
I overworked myself again on the land today. I can barely feel my arms. But, I got about 10 pounds of sugar beets dug up and brought home! I’d been planning to leave them until the first frost, but something has been chomping at the leaves so I decided it was better to bring them in now. I just finished putting up the leaves and stalks in the freezer. I normally don’t like greens, but beet greens are tolerable, and these are almost tasty, so I wanted to make use of them.
I thought my squash would be ready, but it was telling me it wants a little more time. Same with the chickpeas.
Hopefully they won’t get eaten away from me. It seems one neighbor’s horses have gotten loose so often lately that the rumor is going around that he’s turning them loose every night on purpose!