On Postcrossing, I listed in my profile that I'd like to learn these phrases from other nations—when people send me postcards, they come from all nations around the globe—and many senders have been nicely compliant with this request. Here's a summary of what I've got so far:
|Chinese||Ni hao||Hsieh hsieh|
|(Chang) Hao chih|
|Chuvash||Ira kun pultar||Tavta pus||Pite tutla|
|Dank je wel||Heel (erg) lekker|
|German||Hallo||Vielen dank||Sehr lecker|
|Bahasa Indonesia||Selamat pagi (morning)|
Selamat siang (afternoon)
Selamat sore (evening)
Selamat malan (night)
|Terima kasi (banyak)||Enak (sekali)|
|Japanese||Ohayo gozaimasu (morning)|
|Arigato (gozaimasu - polite)||Totemo oishii desu|
|Khmer||Sua s'dei||Au kun||Ch'ngain|
|Lao||Sabaidee||Kop jai||Siep (lai-lai)|
Kia ora (casual)
|Tēnā rawa utu koe||Kakato|
|Taiwanese||Li hou||Lou hsia||Hou chia|
men add "krop"
women add "ka"
|Korp kun krop/ka||Aroi (maak)|
|Vietnamese||Xin chao||Cảm ơn||Ngon wa|
The variations in these answers come, of course, from various regions, various learners of each language, the vagaries of transliteration, and perhaps some discrepancies in handwriting. For instance, I was not able to transliterate the Cyrillic or Kanji hands or replicate them here, but I thought they were awesome nonetheless.
I'm delighted that so many people were so helpful in providing their tongue's phrases for me! I received many contributions for Dutch, Russian, and Chinese, but as one French writer pointed out, there wasn't any French listed (I added that later, on my own). But then, she didn't provide the translation either.