The Annotated Memoirs of Ulysses S Grant is a whopper, 1152 pages. The footnotes more than double the amount of text. But there's so much I don't know about Grant and his presidency and this is such an easy way to learn about it all.
I'm having trouble tearing myself away from Nero Wolfe novels. I've read five of them in less than a week. Now I find another blogger is also a Rex Stout fan, the Trollopian Eve Fisher whose blog is Sleuth Sayers. Here is her post about Wolfe and Samuel Johnson.