Answer: Quarter

One of the problematic aspects of minting metal currency is the rising cost of the very metals you craft the coins with can (and does) outpace the value of the minted coin itself. While many people are aware that it costs more to mint a penny than the penny is worth (1.8 cents to produce with a face value of 1 cent), it is also cost ineffective to mint a nickel (9.4 cents to produce with a face value of 5 cents).

When we get into dime territory, things start to look more favorable; it costs 4.6 cents to produce a dime but the face value is 10 cents. Quarters are even more practical; it costs a mere 10.5 cents to produce a quarter, but the face value is 25 cents.

So how much money does the U.S. Mint lose in the process of minting pennies and nickels? The rising cost of metals started affecting coin production around 2006 and by 2011, penny and nickel production expenses had reached over 100 million dollars per year.