The second best: Being in a room having told someone that Marmite is like a Nutella competitor, and watching them take a big bite of a piece of toast with thick-spread yeast paste on it. 
The best: A similar scenario involving a language barrier, a couple of immature class mates on a school trip abroad,Hasselnussbusser (Hazelnut butter) and Leberkaese ("liver cheese).  Ha, ha, bet three years of Latin-to-help-on-the-SATs isn't looking so good now.