"Ah tu Brutis."
By far my favorite quote of history. The last words of the great Julius Caesar.
You may have been joking, but I'm a nit-picking nerd and had to say that it's actually "Et tu, brute?"
EDIT: Also, there's not any real evidence those were his last words. That's what Shakespeare said they were, but if you research his life you'll find that William Shakespeare was more concerned with entertainment than accuracy. They might have been his last words, but the only thing we have to go on is that it was commonly believed in Shakespeare's day that he said it, and that throughout history most people have assumed he did.
It was also believed in Shakespeare's day that witches had extra tits they used to suckle demons