What is the value of a 1955 US cent?

Answer 1

If it's an ordinary 1955 cent it's worth anywhere from a nickel to 20¢ depending on condition. 1955-S pennies may be worth a few cents more but aren't considered to be particularly rare.

Some coins were struck from an improperly prepared die and have a very visible double image on the front. These can be worth about $900-1000. If it clearly shows a doubled date (i.e. it looks as if the "1955" is struck twice, slightly shifted) you have a much rarer coin and should have it examined by a professional numismatist.