The United States Mint produces Proof Sets specifically for collectors and speculators. Silver Proofs tend to be the standard designs but with the dime, quarter, half dollar, and in some cases the dollar having silver content. Another type of proof set is the Presidential Dollar Proof Set where four special $1 coins are minted each year featuring a president.
2007 had George Washington, John Adams, Thomas Jefferson, and James Madison
2008 had James Monroe, John Quincy Adams, Andrew Jackson, and Martin Van Buren
2009 had William Henry Harrison, John Tyler, James K. Polk, and Zachary Taylor
2010 had Millard Fillmore, Franklin Pierce, James Buchanan, and Abraham Lincoln
2011 had Andrew Johnson, Ulysses S. Grant, Rutherford B. Hayes, and James A. Garfield
2012 had Chester Arthur, Grover Cleveland, Benjamin Harrison, and Grover Cleveland (2nd term)
2013 will have William McKinley, Theodore Roosevelt, William Howard Taft and Woodrow Wilson
2007 had George Washington, John Adams, Thomas Jefferson, and James Madison
2008 had James Monroe, John Quincy Adams, Andrew Jackson, and Martin Van Buren
2009 had William Henry Harrison, John Tyler, James K. Polk, and Zachary Taylor
2010 had Millard Fillmore, Franklin Pierce, James Buchanan, and Abraham Lincoln
2011 had Andrew Johnson, Ulysses S. Grant, Rutherford B. Hayes, and James A. Garfield
2012 had Chester Arthur, Grover Cleveland, Benjamin Harrison, and Grover Cleveland (2nd term)
2013 will have William McKinley, Theodore Roosevelt, William Howard Taft and Woodrow Wilson