Washington established the Cabinet system and recruited the best men for the jobs (an all-star Cabinet incl. Jefferson, Hamilton, Knox, etc.), adroitly upheld American neutrality during the Anglo-French wars, appointed the entire Federal judiciary, gained approval for the construction of six excellent frigates as the foundation of the U.S. Navy, backed Hamilton's reform plans which set the infant republic on sound economic and fiscal footing, put down the Whiskey Rebellion and then pardoned its leaders, saw to the establishment of the Federal City that would later bear his name, etc. He toured every state and knit the country together by his example of character and leadership. Washington got a
lot done in eight years as President.
As for JFK, Big Steel, led by U.S. Steel, was going to raise prices despite earlier assuring the country it wouldn't do so. This would have had a major negative economic impact, and was widely (and correctly, IMHO) interpreted as a shot across the Kennedy White House's bow. By jawboning, steering Federal contracts away from Big Steel and weighing criminal/antitrust prosecutions (somewhat similar to Obama's dealings with BP now, come to think of it), Kennedy prevailed. Here's a pretty good overview of the crisis:
http://www.maryferrell.org/wiki/index.php/JFK_and_Steel,_Bush_and_Oil
I think you give Nixon far too much credit. The opening to China was at the expense of Taiwan, which had been our friend far longer, and is now a much more healthy democracy than the PRC has ever been. He signed the EPA Act, but did nothing to get it passed in the first place; it was hardly a signature policy of the Nixon Administration. The Clean Air Act first passed in 1963, under JFK. Nixon got us out of Vietnam, true, but only after illegally widening the scope of the war including invading Cambodia, and South Vietnam fell just eight months after Nixon left office. (Incidentally, today is the anniversary of the Watergate break-in!)