American Eagles

First issued in 1985 under the Bullion Coin Act, the American Eagle is produced by the American mint and only from gold mined in the United States. Their purity is 22 karat, gold mixed with a small amount of alloy and as such are more durable than the Canadian Maple Leaf.
The American Eagle is available in 1/10, 1/4, 1/2 and 1 ounce variations. Obviously, the $5, $10, $25, and $50 face value of the respective coins are not indicative of their true value. The vast majority of American Eagles are bought by Americans, as they can be placed in IRA account (tax deferral accounts for retirement).
Interestingly enough, the US Tax Agency (IRS) lost a court case (hung jury) where to avoid paying taxes, some American Eagle owners only declared the face value of the coins, not the market value.