What do you say "Oh My GOD" in your language?
Until now I just know in Indonesia and English

Question

Answer

in spanish it's "¡oh, dios mio!" or you could try an even funnier way: "¡ay, diosito!"

Answer

As Italian Blonde already wrote, it's "Oh mio Dio" in Italian; however I find more frequently "Oddio" (the phonetic transcription of "Oh Dio", that is literally "Oh God").

Answer

In Turkish :
Aman Allahım / Aman Tanrım / Aman Yarabbim.

Answer

in chinese, we say: "哦，我的天呐！" or “哦，我的老天爷！" or  "我的妈呀！"
in chinese, we say: "oh,wo de tian na ! " or "oh, wo de lao tian ye ! " or " wo de ma ya ! "

Answer

ღმერთო ჩემო - gmerto chemo - in georgian 
Տեր Աստված - Astvac, ter astvac  - in armenian