Collectible coins include various types such as commemorative coins, rare vintage coins, and error coins. In the United States, the One Dollar coin has seen several designs, including the Sacagawea and presidential series. Jefferson Nickels, minted from 1938 to the present, feature Thomas Jefferson and are notable for the 1979 variety and its significant numismatic attributes. Collectors often seek specific dates, mint marks, and unique features to enhance their collections.