The Rise of Theodore Roosevelt
The Rise of Theodore Roosevelt by Edmund Morris is a masterpiece. (That's probably why it won a Pulitzer...) The smooth flow and colorful vocabulary make it a captivating and truly enjoyable story. It was fascinating as a historical narrative as well; I've read a number of books about TR, and this book was dense with facts new and interesting to me.
This along with Mornings on Horseback provide an amazing view of TR's life leading up to the Presidency. The key difference between them is perspective; Rise is written from TR's perspective, while Mornings is written from the perspective of his family members. The two books are truly complementary, and I recommend them both.
Bottom line: 5 stars. One of the best history books I've ever read, hands down. Probably one of the best books I've ever read period, for that matter. But I'm admittedly a big TR fan, so I'm probably a bit biased.