Formal:
* agradável: This is the most general and formal way to say "nice." It can describe something pleasant, enjoyable, or simply good.
Informal:
* legal: This is a slang term meaning "cool," "nice," or "great." It's very common in everyday speech.
* bom: This simply means "good" but can also be used to mean "nice" in some contexts.
* bonito/bonita: This means "beautiful" or "handsome" but can be used to mean "nice" when talking about people.
Other:
* simpático/simpática: This means "friendly" or "charming" and can be used to describe a person who is nice.
* amigável: This means "friendly" and can be used to describe a person or a place that is nice.
Here are some examples:
* O tempo está agradável hoje. (The weather is nice today.)
* Essa música é legal! (This music is cool!)
* Ele é um homem bom. (He's a nice man.)
* Ela é muito bonita. (She's very pretty.)
* Ele é um homem muito simpático. (He's a very nice man.)
* O restaurante era muito amigável. (The restaurant was very nice.)
Choosing the right word depends on the context and the level of formality you want to convey.