I read 'Rise and Fall of the Third Reich' not too long ago. I highly recommend it. Hitler, in his politics and day to day dealings was a ruthless, badass thug. Think of the most badass movie Godfather/Mob Boss you've ever seen and then mulitply it by 20. His downfall was that he started to believe his own press, got cocky, and then refused to listen to anyone based on his track record of early successes.