Many languages have concepts that either don't exist in other languages, or are exclusive to that particular language. In Arabic for example, the word for translation, ترجمة also means interpretation. After all, that is all a translation is. Some readers may be familiar with the term schadenfreude, a German word that has entered the English nomenclature; meaning to take pleasure in the suffering of others. Here are some other neat German words:
Verlieben - to fall in love. It is such a nice thing to see that a language has a single word for this concept.
Zuklappen - to clap something shut, like a book.
Augenblick - a moment or instant. Literally "eye glimpse".
Treppenwitz - a comeback reply that comes to you after the fact.
Wuseln - to scurry about and mix. Think of a bunch of mice running around inside a box.
Blau - literally means blue, however it can also mean to be sloshed / hammered / plastered.
Kippen - Literally, to tilt. Can also be used as a verb meaning "to kick back a few". It can also mean to vote down a bill, or overturn a ruling.
Gemütlichkeit - an abstract term that can mean coziness. According to Wikipedia: "Its closest equivalent is the word "coziness"; however, rather than merely describing a place that is compact, well-heated and nicely furnished (a cozy room, a cozy flat), Gemütlichkeit connotes the notion of belonging, social acceptance, cheerfulness, the absence of anything hectic and the opportunity to spend quality time."