I think quinoa is pretty good for you. It contains a healthy balance of essential amino acids, it's high in protein, and it's gluten free. It came from South America and was a staple for many historic civilizations of that region.
However, I bet you didn't know that there is a "land meat" that has similar omega-3 to omega-6 fatty acid ratios as is found in wild salmon and other fatty fish. Yep, you heard me right! In fact, this "land meat" not only contains similar or even higher levels of omega-3 fatty acids as wild fatty fish, but without the possible negative compounds such as heavy metals (mercury, etc) and PCBs that can be found in fish many times.
Quinoa is great. I'd also highly recommend Spirulina. You can make it in shakes, take it in capsule or pill form, or sprinkle the powder over salads. It's got an amazing amount of vitamins and minerals, and gives you lots of energy - similar to a coffee buzz without the crash.
Well in actual fact milk is the most complete food that's why babies live on just milk for the first 6 months of life! Apart from iron and vitamin C in which it is deficient it has all the other essential nutrients.
Many natural and organic food that are not processed are good for us. However, anything of too much will not be too good, such as soybeans or even sea weed. You can use dry sea vegetables such as Nori and sprinkle in soup.