Nixon should be on there. He was the worst.
Another historically bad one was Grant.
Oh, and Dubya should be high on the list. Clinton should not. Sure, what he did may not have been the best thing with Monica and all, but it was blown way out of proportion. Overall, he was a great president who led us through a stable period of time.
Oh, and if you want the best President...look no further than Mr. James K. Polk, our 11th president.