I used to never like this tuber when I was kid, but I'm willing to give it a second chance. Putting it above rice is questionable though.
#27 (tie)
Sweet Potato
The sweet potato is actually a very different plant from that other potato, in a whole different Family. In fact, it's most closely related to Morning Glories, which becomes obvious if you happen to see them as plants in bloom - they're almost indistinguishable above ground. The sweet potato is a perennial vine which can grow year-round in the tropics, but has to be harvested before first frost in temperate climates. Its closest wild relatives have relatively thin, barely-edible roots, so we can once again thank natives of Central America who domesticated and bread the sweet tubers we know today well over 5000 years ago. It spread from there to South America, the Caribbean, and even Polynesia all the way to New Zealand long before the age a Western exploration - a fact which supports the idea that Polynesian sailors made contact with the Americans before Europeans got there.
Later on of course they were introduced to pretty much the entire rest of the world, and quickly became an important staple in far-flung regions due to their hardy nature and high nutritional content. Although they have slightly less energy density than cereals like rice and corn, they have considerably more nutrients, especially Vitamins A, C, B6, manganese, potassium and so on, in addition to plenty of dietary fiber. Dried slices of sweet potato are a staple in Uganda, baked whole tubers are a street food in Egypt and China, they're a common tempura ingredient in Japan, and a component of cellophane noodles and candied slices in Korea. On All Saint's Day in Spain they serve roasted sweet potato and chestnuts, they're served alongside ceviche in Peru, and made into a hard sweet jelly in Argentina. They're distilled into a spirit, Imo Jōchū, in Japan, put in salad in the Philippines, and made into a pastry in Taiwan. And of course in the US we have sweet potato casserole, sweet potato pie, and sweet potato fries.
It's just good eatin'!