Edward Teller
Edward Teller should be remembered for his fundamental work on atomic physics and applications of quantum theory to molecular structure. But for better or worse, he is best known as the "Father of the Hydrogen Bomb" - and for his testimony before Congress arguing against the renewal of the security clearance for Robert Oppenheimer.
Oddly enough, after the war Edward - often looked on as a "hawk" in the development of nuclear weapons and national defense - went on record that he felt the atomic bombings of Hiroshima and Nagasaki had been wrong without a prior demonstration of the bomb's power. However, that does not appear to be his thinking at the time. Not only was he not a signatory of the famous "Franck Report" which advocated just that, but he told Leo Szilard that the best way to insure the weapon would not be used again was to drop it on a real target. For what it's worth, Oppie - nowadays often painted as a conscious stricken dove (and called by President Harry Truman a "crybaby") - favored (or at least agreed with) the bomb's military use. And during his own testimony before the House of Un-American Activities (HUAC), he had no hesitation in fingering former associates and students as communists, even when they were not.
Edward left his memoirs and there is a recently published biography which will give you more information than you'll find if you click here.