Answer:
They both have a "little state" complex. Slovaks are quiet (and well.. not many people know about them) because of it, but Czechs are pretty much loud and make fun of everyone who live in country that is bigger than Czech republic. For example - USA, Russia, China, Japan... But both Slovaks and Czechs love alcohol. Slovaks prefer brandy, Czechs beer (and Czech beer is actually better than Germany) ;). And remember this - most of the Slovaks hate Czechs.