From Laura K. Lawless,
Your Guide to French Language.
Learn some different ways to say "good" in French
If you want to make your French sound more, well, French, one place to start is with your vocabulary. In French classes, you tend to learn the most common, basic terms. Bon is one example of a very common word that has numerous synonyms to choose between, in both normal and informal registers. Take a look at this lesson to learn some different ways to say "good." Click on each word to hear it pronounced.
nice, pleasant, pleasing
Il est toujours agréable de vous voir
It's always nice to see you
C'était une conversation agréable
It was a pleasant conversation
good, moral, right, healthy
Ça serait bien !
That would be good!
Ce sont des gens bien
They are good (moral) people
Bien is invariable and can be used as an adjective only with copular verbs, like être
Bien is more commonly used as an adverb that means "well."
Bonne idée !
C'est un bon étudiant
He's a good student
Lesson on bon vs bien
Il a répondu en excellent français
He responded in excellent/flawless French
C'est excellent !
Il a un talent exceptionnel
He has exceptional talent / He is exceptionally talented
C'est une occasion exceptionnelle
It's an exceptional opportunity
Note that exceptionnel is a semi-false cognate, as it can also describe something as an exception to the norm:
un numéro exceptionnel - special issue
C'est un livre extraordinaire
It's an extraordinary book
Elle a connu un succès extraordinaire
She has had extraordinary / immense success
As in English, extraordinaire can mean "out of the ordinary" without necessarily meaning really good:
Il a eu un accident extraordinaire - He had an extraordinary/unusual accident
C'était un spectacle merveilleux
It was a wonderful performance/show
Le vin est merveilleux cette année
The wine is excellent this year
Il est remarquable qu'elle ne soit pas au courant
It's remarkable that she doesn't know what's going on
C'est un homme remarquable
He's a remarkable man