Best American presidents?

>Sees every single president up to the end of Vietnam in Poll
>Tear comes out of eye cuz 'USA

Seriously though, President Truman was our greatest leader, for the following reasons:

1. WWII.

While many consider the dropping of the Atomic Bombs to be a dark chapter of American history, I'd argue the contrary. American military experts had estimated 1 million American casualties in the event of an invasion of Japan, while up to 10 million Japanese were estimated to die in such an event. If we compare death tolls, the A-Bombs killed up to 230,000. That's a massive difference.

And yes, while it is true that our conventional air campaign could have also ended the war, that risked Soviet intervention. The Soviets had already invaded Manchuria, Northern Korea and Sakhalin by August 15th, V-J Day. A conventional air campaign would have meant that the peace would have taken longer, meaning South Korea and possibly even Northern Japan could have fallen to communism by the time the Emperor would agree to peace.

2. Racial Integration.

Harry Truman's presidency saw the first executively driven campaign to integrate the country, with Truman issuing an executive order integrating the Armed Forces and the Civil Service.

3. Cold War.

As the first president of the Cold War, Truman's initial actions were to be critical for the next 40 years to follow. All in all, he was very successful.

The Marshall Plan resulted in 13 billion dollars being sent to help rebuild Western Europe, which was both a massive PR move for the United States and it helped establish Western Europe as a stable, capitalist force able to resist communist expansion (He did a very similar action with Japan). He also sent funds and arms to the Greek capitalist forces in the Greek Civil War, ultimately helping them achieve victory against the communists, and provided funds to the Turks after Stalin threatened them. The Truman Doctrine, which Truman espoused, also placed a focus on containing communism as opposed to actively attempting to exterminate it wherever it was so as to prevent a potential major conflict with the Second World. 

He also wasn't afraid to stand up to the Soviet Union, forming NATO in 1949 with Western Europe, Canada, and Turkey, and airdropping supplies into West Berlin after Stalin attempted to blockade the city off and force the West to cede it to East Germany.

4. Israel

Harry Truman, against the advice of some of his closest advisors, had the U.S recognize Israel 11 minutes after they declared independence in 1948. This would lead to U.S support of Israel and helped to ensure that the Jews would have a place to live.

The only gripe I have against Truman is regarding Asia. He wasn't able to prevent Communist victory in the Chinese Civil War (Then again, it would have been tremendously difficult to prevent that) and brought the U.S into a costly, drawn out war in Korea from 1950-1953 (It was kind of essential though to prevent complete destruction of the Rhee Regime in South Korea).