I've had occasion to meet him once, when he gave a lecture to a relatively small audience in the very nice library in the Old College (part of the University of Edinburgh) many years ago. There was actually a point in attending his talk, as in he said something I found new. He said the Soviet Union, when it was established in 1917-ish, was not an advance in democracy or a regression in economics. It was relatively indifferent in democracy and a fantastic advance in economics over the hopeless feudal system that existed in Tsarist Russia.
Galbraith proceeded to claim that the Soviet union continued to be an overwhelming economic success for decades, and eventually failed not due to economic stagnation (which is the textbook cause believed by westerners) but simply because soviet society had grown modern and relatively affluent to the point that Soviet politics and Soviet economics, which both failed to modernise, were antiquated for it. To put it another way (my metaphor), the patient became well enough to want rid of the medication.
I paraphrase wildly, and blame me if I've not relayed the message correctly. It was at least 10 years ago. But i did find it fascinating and I still would like to read a good, believable account of why the Soviet Union collapsed.
From the Washnigtom post: Iconoclastic Economist John Kenneth Galbraith Dies