Formal:
* Mabango - This literally means "fragrant," but it can be used sarcastically to mean "stinky."
* Masangsang - This is a more direct word for "stinky," but it can also be used to describe a strong, pungent smell.
Informal:
* Baho - This is the most common and direct word for "stinky."
* Amoy putok - This literally means "smells like fart" and is used to describe a very strong and unpleasant smell.
Example:
* "Ang baho ng basurahan." (The trash can is stinky.)
* "Ang masangsang na amoy ng isda." (The strong smell of fish.)
* "Ang mabango mo naman." (You're so stinky.) *sarcastic*
The best word to use will depend on the situation and the level of formality required.