Informal:
* "Bravu!" (pronounced "brah-voo") - This is a very common and versatile way to express praise, meaning "good job!" or "well done!" It can be used for a variety of situations, from finishing a task to achieving a goal.
* "Magnificu!" (pronounced "mahn-ni-fee-koo") - This means "magnificent!" and is a strong expression of approval. It's suitable for impressive achievements or outstanding work.
* "Stupinnu!" (pronounced "stoo-pee-noo") - This means "amazing!" and is used for something truly impressive or unexpected.
* "A piaciutu!" (pronounced "ah pee-ah-chee-oo-too") - This means "I liked it!" or "It's pleasing!" and can be used for work that is appreciated.
Formal:
* "Travagghiu magnificu!" (pronounced "trah-vah-jee-oo mahn-ni-fee-koo") - This literally translates to "Magnificent work!" and is a more formal way to express praise.
* "Travagghiu stupinnanti!" (pronounced "trah-vah-jee-oo stoo-pee-nahn-tee") - This translates to "Amazing work!" and is another formal option.
Bonus:
* You can also add "A piaciutu assai!" (pronounced "ah pee-ah-chee-oo-too ah-ssah-ee") which means "I liked it very much!" for an extra dose of praise.
Remember that the best way to say "great work" in Sicilian depends on the specific situation and your relationship with the person you are talking to.