* 1944 Steel Penny: Another steel penny was made in 1944, but this one had a copper coating. About 316 million of these pennies were made, making them less rare than the 1943 steel penny.
* 1943-D Penny: This penny was minted at the Denver mint, but it was never released into circulation. It is estimated that only about 10,000 of these pennies were made, making them extremely rare.
* 1955 Doubled Die Penny: This penny has a doubled die error, which means that the dies used to strike the penny were slightly misaligned. This resulted in a faint second image of the Liberty Bell and the date. It is estimated that about 20,000 of these pennies were made, making them relatively rare.
* 1969-S Proof Penny: This penny was minted at the San Francisco mint, but it was never released into circulation. It is estimated that only about 5,000 of these pennies were made, making them extremely rare.