Formal:
* Очень хорошо (óchen' horoshó) - This is the most common and formal way to say "very good."
Informal:
* Отлично (otlíchno) - This is a more informal and enthusiastic way to say "very good," similar to "excellent."
* Хорошо (horoshó) - This is a more casual way to say "good," and can also be used to mean "very good" in some contexts.
* Круто (krúto) - This is a very informal way to say "very good," similar to "cool" or "awesome."
Other options:
* Прекрасно (prekrásno) - This translates to "perfectly" or "beautifully," and can be used to express strong approval.
* Замечательно (zaměchatel'no) - This means "remarkably" or "wonderfully," and can also be used to express strong approval.
The best way to choose the right phrase depends on the situation and your relationship with the person you're talking to.