Collectible coins encompass various types, including historical currency, commemorative coins, and precious metal pieces. The United States has produced notable collectible coins, such as the $20 golden double eagle, which features stunning designs and significant historical value. Additionally, the Flying Eagle cent, minted from 1856 to 1858, is highly sought after due to its unique design and limited production, making it a popular choice among numismatists. These coins often capture aspects of American heritage and artistry, adding to their desirability among collectors.