“Winston Churchill said that democracy was the worst possible form of government, except for all the others. Maybe we can say the same about capitalism. For all of its faults, it gives most hardworking people a chance to improve themselves economically, even as the deck is stacked in favor of the privileged few… Here are the choices most of us face in such a system: Get bitter or get busy.”

Speech in the House of Commons (11 November 1947), published in 206–07 The Official Report, House of Commons (5th Series), 11 November 1947, vol. 444, cc. http://hansard.millbanksystems.com/commons/1947/nov/11/parliament-bill#column_206
Post-war years (1945–1955)
Variant: Democracy is the worst form of government, except all the others that have been tried.
Context: Many forms of Government have been tried and will be tried in this world of sin and woe. No one pretends that democracy is perfect or all-wise. Indeed, it has been said that democracy is the worst form of government except all those other forms that have been tried from time to time.

2016, State of the Union address (January 2016)
Context: But democracy does require basic bonds of trust between its citizens. It doesn't – it doesn't work if we think the people who disagree with us are all motivated by malice, it doesn't work if we think that our political opponents are unpatriotic or trying to weaken America. Democracy grinds to a halt without a willingness to compromise or when even basic facts are contested or when we listen only to those who agree with us. Our public life withers when only the most extreme voices get all the attention. And most of all, democracy breaks down when the average person feels their voice doesn't matter; that the system is rigged in favor of the rich or the powerful or some special interest. [... ] So, my fellow Americans, whatever you may believe, whether you prefer one party or no party, whether you supported my agenda or fought as hard as you could against it, our collective futures depends on your willingness to uphold your duties as a citizen, to vote, to speak out, to stand up for others, especially the weak, especially the vulnerable, knowing that each of us is only here because somebody somewhere stood up for us. We need every American to stay active in our public life and not just during election time so that our public life reflects the goodness and the decency that I see in the American people every single day.

CNN interview, 2011-06-19. http://www.bloomberg.com/news/2011-06-19/taliban-u-s-talks-very-preliminary-defense-chief-gates-says.html

János Kornai, in "An Interview with János Kornai : Interviewed by Olivier Blanchard", Macroeconomic Dynamics, 1999

Milton Friedman - Big Business, Big Government http://www.youtube.com/watch?v=R_T0WF-uCWg

Source: When Corporations Rule the World (1995,2015), pp. 20-21

Source: Stranger in a Strange Land

That is where we are in Nigeria today because the choices made by citizens with their ballots are being increasingly rendered useless. And this threat to ‘the legitimacy on the system’ is coming from our courts, including the highest court in the country whose decisions are not only final but affect those of lower courts.
Politics In Nigeria: When Judges Become Our Electoral College https://www.opinionnigeria.com/politics-in-nigeria-when-judges-become-our-electoral-college-by-olusegun-adeniyi/ (February 28, 2020), Opinion Nigeria.

Speech in the House of Commons (11 November 1947), published in 206–07 The Official Report, House of Commons (5th Series), 11 November 1947, vol. 444, cc. http://hansard.millbanksystems.com/commons/1947/nov/11/parliament-bill#column_206
Post-war years (1945–1955)