Here are a few nice ones, I can’t really pick:

“Capitalism is the extraordinary belief that the nastiest of men for the nastiest of motives will somehow work together for the benefit of all.” - John Maynard Keynes

(You can also apply this one to proprietary software vs. Free software (don’t say open source in my presence))

“The tyrants are only great because we are on our knees.” - Étienne de La Boétie

“Those who do not move, do not notice their chains.” - Rosa Luxemburg