Most Expensive

• 1933 Double Eagle (Americanhistory.si.edu)
  
  The most expensive coin in the world is the 1933 gold Double Eagle, of which the U.S. Mint only printed 445,500. A single coin sold in July 2002 for $7.5 million.
  
  

Silver Dollar

• 1804 Original (Coinfacts.com)
  
  The 1804 Original (the original reverse designed for this line) sold at auction in August 1999 for $4.1 million. In this edition, the word "states" is nearly centered over the clouds as opposed to being shifted farther left in the second reverse.
  
  

MCMVII Double Eagle

• Double Eagle obverse (Smithsonian Institution)
  
  The MCMVII ultra-high relief, lettered edge is a gold coin worth $20 in 1907. It sold at auction in November 2005 for $2.9 million. It looks identical to the 1933 gold Double Eagle minus the lettering on the edge.
  
  

Brasher Doubloon

• 1787 Brasher Doubloon, EB on wing (Tom Mulvaney, Smithsonian Institution)
  
  The next two most expensive coins were produced before establishment of the U.S. Mint by New York goldsmith and jeweler Ephraim Brasher in 1787. Valued at $15 in New York currency, the version with the author's initials on the breast of an eagle sold for $2.9 million, while the version with his initials on the bird's wing sold for $2.4 million, both in January 2005.
  
  

1927-D Double Eagle

• 1927-D Double Eagle reverse (Tom Mulvaney, Smithsonian Institution)
  
  The 1927-D Double Eagle sold for $1.8 million in November 2005. It looks identical to the 1933 gold Double Eagle.