Formal:
* Génial: This is a very common and versatile word, often used to express "great," "brilliant," or "wonderful."
* Extraordinaire: This is a more formal word, meaning "extraordinary" or "remarkable."
* Fantastique: This is a more informal word, meaning "fantastic" or "fabulous."
Informal:
* Super: This is a very casual word, similar to "super" in English.
* Canon: This slang term is often used to express "amazing" or "top-notch."
* Dingue: This slang term literally means "crazy" but can be used to express "awesome" or "incredible."
* Trop bien: This literally means "too good," and is a common way to express "awesome" among young people.
Other options:
* Impressionnant: This means "impressive" or "amazing."
* Stupéfiant: This means "astonishing" or "mind-blowing."
* Excellent: This is a more general word for "excellent" or "great."
The best translation will depend on the specific situation and the level of formality you want to convey.