What person's autograph is worth the most?

Who’s autograph (person can be living or dead) is worth the most money in the world? Is it Babe Ruth? Abe Lincoln? Someone not so well known, but still has the most costly autograph?

Or is it un-answerable?

When I was a kid, I remember Guiness saying it was Button Gwinnett (sp?), a signer of the Declaration of Independence and apparently little else.
(I used to read Guiness over and over!)
Not sure if old Button is still #1.

According to this site, the answer to your question is William Shakespeare.

Sweet, I guess I could’ve googled it, but have come to like this place and it’s variety of answers. Thanks. Could you imagine owning that autograph?