The Greatest United States Presidents in history, ranked from best to worst. Who's the greatest U.S. president? Anyone can vote on or make their own version of this collaborative list of the men who shaped American policy - a fascinating insight into all the US Presidents and how their presidencies were perceived. Who were the best presidents? We expect this list of the Chief Executives to change over time as history's perceptions also change.And be sure to check out Ranker's ultimate list of the Worst-Ever US Presidents as well, for comparison's sake.