The momentous and scandalous discovery of evolution can only be matched in the field of psychology by the discovery of the unconscious. All of the other responses here do not come close in importance to those massive upheavals you listed.
I'll only admit I've cheated a little: that Freud's contribution was a scientific one is not an assertion that is "generally regarded as correct." But Freud believed himself to be a scientist and frankly I agree. It's not like Einstein, Wegener, and Darwin are uncontested figures, but certainly Freud is much more so.