When I was little, my mother (who served as a Red Cross worker during World War II) used to tell me stories of people in Weimar Germany taking wheelbarrows full of money to the store to buy a loaf of bread. “Haha,” I thought, “that’s a good one,” being too young to really get the concept.
German woman burning banknotes, which burned longer than the wood that they would buy.
Then I grew up and traveled to Serbia, where I discovered that hyperinflation is not relegated to the furnaces of history.
This is the 500 billion Dinar note that was printed at the end of Serbia’s period of hyperinflation (I also have a 50,000,000,000 Dinar note as well) and I thought these were quite unique.  Until I heard about what happened in Zimbabwe.
Off to buy a pack of gum
Even this didn’t help the situation; From Wikipedia, “The Zimbabwean dollar is no longer in active use after it was officially suspended by the government due to hyperinflation. The United States dollar ($), South African rand (R), Botswana pula (P), Pound sterling (£) and Euro (€) are now used instead. The United States dollar has been adopted as the official currency for all government transactions.”
But none of these monsters can touch what happened in Hungary in 1946:
This is the 100 quintillion pengő note, the largest banknote ever issued for public circulation. That’s 100,000,000,000,000,000,000, or 1020 pengő, which is a lot of pengő no matter how you slice them.
One rather interesting side-effect of inflation in Greece (before they gave up the Drachma in favor of the Euro) was that 5, 10 and 20 lepta coins became so worthless that it was cheaper to use them as washers than to go to the store and buy them.
Prices keep going up here in the USA in the early years of the 21st century, but I’m grateful we’ve never experienced this sort of madness here. Well, almost never.
Just enough for 3 gallons of gas. 
The Old Wolf has spoken.
 This one is still unique to me, because I have one.
 The $100,000 dollar note was never circulated – it was used only for transactions between Federal Reserve banks.