Good on ya
Well done. Can be sincere or sarcastic depending on tone.
Person 1"Finished the half marathon."
Person 2"Good on ya, mate."
You'll also hear
Onyashortened
Good onya, mumfrom the Australian Made ads
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While you're here
You're a good person. Said to thank someone, or to praise them to others.
Loyal and thoroughly Australian.
He is as good a person as you will ever meet.
Very fit and strong.
Excellent. Old-fashioned now and mostly used jokingly.
Something or someone excellent.