Formal:
* Très amusant (literally "very amusing") - This is the most straightforward and common translation.
* Extrêmement amusant (literally "extremely amusing") - This conveys a stronger sense of amusement.
* Très divertissant (literally "very entertaining") - This emphasizes the enjoyment aspect of the situation.
Informal:
* Trop drôle (literally "too funny") - This is a very common way to express amusement in informal situations.
* Super marrant (literally "super funny") - This is a slangy expression that is very common among younger people.
* Tellement rigolo (literally "so funny") - This is another informal way to express amusement.
Other options:
* Excellent (excellent) - This can be used to express enjoyment and amusement.
* Génial (awesome) - This is a more informal expression that can be used to express amusement.
The best translation will depend on the specific context and the desired level of formality.