Formal:
* Grand Dieu! (literally "Great God!") - This is the most literal translation and is often used in a dramatic or surprised tone.
* Mon Dieu! (My God!) - This is a more common and less dramatic expression of surprise or dismay.
Informal:
* Oh là là! - This is a very common expression of surprise, disbelief, or even exasperation.
* Zut alors! - This is a slightly stronger expression of annoyance or frustration.
* Sacré bleu! - This is a more playful and informal expression of surprise, often used in a humorous context.
Other options:
* C'est pas possible! (It's not possible!) - This expresses disbelief or frustration.
* Quelle horreur! (What horror!) - This conveys a sense of disgust or horror.
The best translation will depend on the specific situation and the tone you want to convey.