I enjoy showing foreigners how fake US "money" is
The copper ring on quarters, revealing that it's just a cupronickel face over a copper core
Flipping an old penny vs a new one to hear the ring of the copper vs the dead thunk of the zinc
The $50 1oz Gold Eagle that the US government will sell you for about $2,000
The Federal Reserve Note (note=debt) that's also legal tender for ALL debts... Even itself