What autobiographies do you recommend?

I've recently found that I really enjoy history. I know that autobiographies aren't always a good way to get an accurate portrayal of a person, but they are usually quite interesting.

So, whos autobiography would you guys recommend? I'm sure we have some history buffs here.

So far I have autobiographies by Andrew Carnegie, George W. Bush, Ray Kroc, and Clarence Thomas. Getting Ulysses S. Grant's soon.