Poll

So I have been conducting a poll among random people I know as to who are the five worst Presidents in US history. I personally would list W, Hoover, Grant, Andrew Johnson, and Taft, but my informal poll has W and Nixon running neck and neck as worst ever, I don't even put Nixon in the top ten, sure he was a creepy bastard but in terms of actual harm done to the nation, there are much better choices, give me some feedback.