President Carter is the best TTM signer. It takes him about 3 weeks to respond. He does occasionally send out preprints, but if you send him something to sign, he will sign it for you.
The Most Honorable James E. Carter
c/o Office Of Jimmy Carter
Correspondence Assistant
1 Copenhill Avenue North East
Atlanta, GA 30307-1400
I had a few recent successes from President Ford, but he doesn't usually sign autographs anymore. Right now, he's in the hospital. He's really frail (93 years old), so I think it would be best NOT to request an autograph from him. His Library sells signed copies of his autobiography for $500. His address is available on almost any autograph related website, including the Fanmail database, but I don't feel comfortable posting it here. I think he deserves his privacy now that he is older private citizen.
http://www.fordlibrarymuseum.gov/museum ... atalog.asp
President George W. Bush CANNOT sign autographs through the mail for security reasons. He can sign in person. Evidently, there's some type of law preventing any President in office from sending out autographs in the mail. Although, I have seen hand written notes that were sent out from the White House. I think you can get one if you're a big GOP supporter.
President George W. Bush
The White House
1600 Pennsylvania Avenue NW
Washington, D.C. 20500
President George H.W. Bush (the father "#41") does send out hand signed autographs, but he does so very rarely. It took me YEARS to get a hand signed autograph from him (I received it this past Saturday). His library sells signed items. The prices range from $200 - $700.
http://www.museumstore.com
President George H.W. Bush
10000 Memorial Drive
Suite 900
Houston, TX 77024-3412
President Clinton sends out preprints or autopen signatures. He will not sign an autograph through the mail. You can buy a signed copy of his autobiography, "My Life", from the Clinton Foundation for a tax deductible donation of $500.
http://www.clintonfoundation.org
The Most Honorable William Jefferson Clinton
55 West 125th Street
New York, NY 10027-4516
The Reagan Foundation and Library sells various books signed by President Reagan for $4,000.
http://www.reaganlibrary.com
The Nixon Foundation sells signed copies of President Nixon's books. The prices range from $750 - $4,000.
http://www.nixonfoundation.org