I have read 4 books on him
>Napoleon, by Vince Cronin
>Napoleon the Great, by Andrew Roberts
>Moscow 1812, by Adam Zamoyski
>Rites of Peace, by Adam Zamoyski (this one is less about him personally, more about the Congress of Vienna and surrounding events.)
All were good, but you know, Roberts' Napoleon bio isn't perfect. Does it have more information than Cronin? Yes, but do does a textbook. Robert's biography is missing readability. It's missing poetry. However, it is not missing casualty counts and missing banner counts for every single engagement of his career. I understand studying the battles and campaigns matters, but not like this. David Chandler's Campaigns of Napoleon is what you want (I haven't read it yet, but it's the Bible of Napoleonic Campaigns.)
Roberts tries to make it so that his book is a one-stop-shop for all things Napoleon, and if you had to read one book on him, it is a fine choice. But you're not going to read just one book on him. Anyway if you want to know what Napoleon meant by "what a novel my life has been," read Cronin. (f you want a 1000 page version of a Wikipedia article, go for it. Modern historians are lousy stylists.