Mine is schadenfreude which I must confess I first heard on The Simpsons. From the Wiki link:
What’s yours?
Kerfuffle
Anaranjado y miércoles.
Ananas. No, I can’t tell you why.
Titicaca
That has four L’s in a row. Not fair!
I like the word kaj. It means “and” in Esperanto.
aarschgnoddle, the Pennsylvania Dutch word for dingleberry.
The portuguese word “saudade”. Regardless of how you’re training to explain what it means, a portuguese speaker will always tell you you didn’t really get it.
I looked up and noticed that wikipedia has full page article just about this word. It proposes the following definition
Towards the end of the article it mentions as a possible equivalent the equally interesting finish word “kaiho”
Even though it ads that both words aren’t really synonymous because :
Since Schadenfreude is already taken, I must go to my second pick, which is really just a swearword, and that is “du”, the Vietnamese for “fuck” (sorry, I can’t do the accents).
Yes, it’s just a straightforward translation, so what’s so special about it?
Well… it’s in the way it’s said. The falling tone is fantastic for expressing disdain, weariness, or disgust. Faked disdain is a big part of friendly Vietnamese banter, and my Vietnamese workmates and friends and I will often greet one another with, “aaaah… Duuuu…” whilst simultaneously poointing towards the other guy with a palm upward gesture and a facial expression of eyes-screwed up disappointment. It’s quite funny if you do it right. There’s a touch of a Yiddish-style “Oy. Another asshole. Eh, what can ya do?” about it.
For me it’s kaput. There are times when kaput express the situation admiringly. It also drives the little girl next door bonkers.
Like Loaded (nah, seriously, I’m not stalking ya’ mate! 
) the first word that came to my mind was also a swearword, malacka (or malacca or malaka…never saw it written alas so the spelling was always up for conjecture).
I went to a predominantly wog populated school as a kid, so Greek obscenities littered the playground as much as the Twisties and Four’n’Twenty pie wrappers.
That’s why I love multiculturalism. 
I opened this thread to mention saudade[sup]1[/sup], but now clairobscur has stolen the word away from me. I wave farewell to it as it sails beyond the horizon into the West, and although I hope that it will one day return to me, I fear that I have lost it forever. Alas, my heart is full of sorrow, but I know that it was fate that lent wings to those Parisian keyboarding fingers…
However, as [Portuguese] Saudade is to Fado, so [Spanish] Duende is to Flamenco[sup]2[/sup], and thus will I yet have my fiery revenge!
( [sup]1[/sup]I heard a friend (a professional singer) perform last Sunday, and am currently composing an e-mail suggesting that she try singing fado, since her voice has a wonderful quality of saudade to it.)
( [sup]2[/sup]To the extent that if you’re not Portuguese or Spanish, you “just don’t get it”. However, in both cases it’s fun pretending that you do.)
Cafe.
Removed
Just to offset du (đụ ), I’ll add the Vietnamese duyen (duyên), which by itself means charm or grace, but can also be roughly translated as the fate that allow soulmates to find each other in a chaotic world, and that binds them together forever after.
Chutzpah
Hiraeth - it’s Welsh and has no direct English translation, but basically it means a yearning or longing for him.
Val Bethell describes it like this: “Hiraeth - the link with the long-forgotten past, the language of the soul, the call from the inner self. Half forgotten - fraction remembered. It speaks from the rocks, from the earth, from the trees and in the waves. It’s always there.”
The German word for cotton is Baumwolle.
Literally, it means “tree wool.” I can’t think of more poetic description of cotton.