I'd like to read the best biographies of historical figures that people of MeFi consider important, interesting. The best would be one authorative biography per person, the one considered to be authorative, even if it has it's own problems. Examples inside.
Two examples pop into my mind: Robert Caro's The Power Broker and Ray Monk's Ludwig Wittgenstein: The Duty of Genius. Both are doorstoppers, very heavily sourced, comprehensive and considered definitive.