Formal:
* Tenha uma ótima noite! (This is the most common and versatile option)
* Desejo-lhe uma noite maravilhosa! (This is a more elaborate and elegant way to say it)
Informal:
* Boa noite! (This is a general greeting that can also be used to wish someone a good evening)
* Que a sua noite seja maravilhosa! (This is a more personal and friendly way to say it)
* Tenha uma noite top! (This is a slang expression meaning "have a great night" - it's not formal, but it's common among young people)
You can also add a specific detail to make it more personal:
* Tenha uma ótima noite de descanso! (Have a great night of rest!)
* Tenha uma ótima noite de diversão! (Have a great night of fun!)
Choose the option that best fits the situation and your relationship with the person you're talking to! 😊