By whom?

The French revolution had a much larger effect on European political and social norms. With out the French Revolution, no Napoleon, no nationalism in the German states, no spreading of basic Human Rights by great French thinkers and philosophers, no revolutions in the first half of the 19th century and social and political reform that has shaped Europe to what it is today.

The American Revolution had smaller effects, but it didn't directly influence Europe as the French did. What the American Revolution did was prove to some European free thinkers, is that the kings and emperors could be overthrown and the people could self govern.

In most of Europe, the "American Revolution" is referred to as the War of Independence, not a as revolution. The French Revolution toppled a thousand year old ancien regime, the American Revolution granted colonies their independence.