If you have to name one essentially Hungarian thing, one thing that anyone will name if you stop them on the street back home: it is the Túró Rudi.
(I'll give you a minute to get over the nausea. You are welcome.)
It actually tastes like heaven and unicorns (whatever unicorns taste like). There are other variations, some have different flavors of fruit jam in the middle, and some are coated in milk chocolate (also known as blasphemy). Some sacred sites around the country even have shrines known as the Túró Rudi Dispenser Machines. For the sacrifice of your lunch money, they give you a taste of happiness:
The full name of the product is Piros Pöttyös Túró Rudi, or Red Dotted Túró Rudi, to mark the original flavor and distance it for knock-offs such as the Fitness Rudi (eck). As the marketing tagline says: "Red Dots is the Real Thing." Túró means cottage cheese, while Rudi is (according to folk linguistics) is short for Rudolf. This often trips up Hungarian students at English language exams (and American teachers, trying to decipher why this "Cottage Cheese Rudolf" guy tastes to good).
Some heretics claim that Túró Rudi was first invented in the Soviet Union, and we only re-branded it in 1968, adding the red dots and the myth. But sshhh.
The tragedy of the Túró Rudi is that it does not carry well over long distances (dairy product), which makes it the No. 1 reason any expat will visit Hungary periodically, and gorge on it for a week or two (I know that's why I do every year). The good news is that it can also be made at home, although the results may vary in taste. The filling needs cottage cheese, and 1/10 of the amount powdered sugar and butter (and sometimes lemon peel for flavor). The coating is just dark chocolate. But if you want the real experience, I suggest a pilgrimage to the holy land of Túró Rudi. It will be an enlightening experience. Amen.
(Blessed are the makers of all dairy products.)