Natto

Natto is native to Japan, one of the most influential places in the world for food. However they produced nato, one of the worst tasting foods on the planet. 

 Natto are fermented soybeans, a bacteria called Bacillus subtilis. May foods are fermented but Natto is by far the winner, imagine blue cheese but slimmy slippery and smelling like a pair of gym socks.
I lived in Japan and travelled Asia almost a decade ago, but still vividly remember trying this, in all the foods I have ever tried. Natto is one of the top three easily.
Natto is served cold on top of rice, in the morning! Imagine waking up after a nights drinking to be greated by something like that. 
Perhaps Anthony Bourdain said it best "Given a choice between eating natto or digging up my old dog Pucci (dead for thirty five years) and making rillettes out of him? Sorry, Pucci." 
So Natto give it a try! It's good for you.