Collectible coins encompass a variety of types, including historical, commemorative, and error coins. In the United States, significant examples include the Fifty Cents coins, often associated with the half dollar denomination, and the Flying Eagle Cent, which was produced in 1857 and features a design of an eagle in flight. The Flying Eagle Cent is particularly notable for its role in the transition from large cents to smaller denominations, with its unique design and limited mintage contributing to its appeal among numismatists.