1943.
In 1943, to save copper for the war effort pennies were struck in zinc coated steel, however some copper blanks made their way into the press and were struck by accident, there are only a handful of known genuine examples of a copper 1943 penny and they can be worth in excess of 1 million dollars. However, steel 1943 pennies are incredibly common and are worth about 5 cents in circulated condition or a buck or two if uncirculated. An easy way to check if you have a steel or a copper penny is to hold a magnet up to it, the magnet will stick to the steel penny and not the copper penny.
1937 penny
The rarest and most valuable Lincoln cent that isn't an error is the 1909-S with VDB on it. The rarest and most valuable error Lincoln cent is the 1943 copper penny.
1970-S
Only around 5 cents. They're not as valuable as most people believe.
Assuming you mean Wheat penny's, the 1909-S V.D.B., 1914-D & 1931-S are the icons of the series.
The most valuable ones are the 1943 copper penny, and the even more rare 1944 steel penny.
As far as general circulation coins are concerned, easily the most valuable Australian Penny is the 1930 Penny and the most valuable Halfpenny would be the 1923 Halfpenny.
1794/5 Flowing hair silver/copper dollar
1937 penny
the most valuable is the penny in the us has a head on the front and back hope this helped :) :) :) :) :)
The Queen Victoria, penny-red, plate 77, one penny stamp.
The rarest and most valuable Lincoln cent that isn't an error is the 1909-S with VDB on it. The rarest and most valuable error Lincoln cent is the 1943 copper penny.
The 1909-S V.D.B.
1970-S
At least for Lincoln cents, the most valuable by far is the 1909-S VDB.
A miss-stamped penny may be very valuable, especially if it is in excellent condition. Such a coin can be worth hundreds of dollars, depending on condition, year, and the nature of the error. Not all such coins are valuable, and typically it takes a coin expert to determine if a particular coin is valuable or not.
Only around 5 cents. They're not as valuable as most people believe.