The most important sentence for the USA is what is printed on the money: In God We Trust
Says it all, really. And explains all the great parts....and all the weird parts of the country.
For Germany, it is: Bier ist Bier und Dienst ist Dienst. Beer is beer and work is work.
This sums up why Germans seem so humorless and "machine-like" to other nations...and why they don't see themselves that way.
whats the most important quote you can say about your country