Fools. The second (if not the first) most important language is the language of luurrrrve.
How about sign language? Sure, there are a few different versions, but not as many as spoken languages, some of it it intuitive even to people who have never encountered it before and it does include an extra portion of the communicatively-challenged population (while excluding another, sadly). Sign language already closes the Frech/American divide -maybe it can also resolve the freedom fries issue?
Or computer languages? Binary? Can we call Binary a language? It's a pretty damn important communication concept, that's for sure. at some level. Barcodes and shit.