One cool and rarely discussed effect of the French Revolution is the architecture of Paris and other major French cities.
During the French Revolution, rebels would create barricades in the streets to prevent the army from getting through to attack rebels, resupply, or generally get anywhere. Following the revolution, the decimated cities were rebuilt with very wide streets primary designed to prevent future barricades!
The French Revolution also resulted in some of the greatest philosophers of the modern age, whose works continue to influence modern democracy and policy: Rousseau, Montesquieu, Voltaire, and Diderot, to name just a few. One of the most important ideas that continues to prevail today is the idea of checks and balances in power between different groups so that one demographic, such as the uber-wealthy, does not control everything in a country.