So who would you say is the worst top three Presidents in recent American History (50 years) and why?

Obama, Clinton and Carter in that order. Problem with Bush is, there is no concrete evidence against him as well as for him. In the case of Bush his value is so partisan that he cannot be accurately judged here. Obama, on the other hand, is disgusting many of his own constituencies and just about the only thing he can run on is the fact that the opponent probably disgusts them even more. Of course the opponent to be has not been a president yet.