1 Dollar (Apollo 11 50th Anniversary)

The Apollo 11 Silver Dollar: a coin curved like a spacesuit visor

Most coins are flat discs. This one is a shallow dome — concave on the front, bulging on the back — so that the reverse cradles a tiny, mirrored reflection of Buzz Aldrin's helmet visor, exactly as it looked on the Moon. It was the first US commemorative dollar ever struck in pure .999 silver, and its winning face came not from a Mint staff artist but from a Maine sculptor who had been entering coin contests, and losing, for twenty years.