Well you would want to live somewhere that suits your life style, If your into the beaches then QLD would be the place to be, BUT your looking at spending alot of money in Life Style since its very expensive.
NSW/Sydney - Pretty Ratty, its popular but its just 1 of them places between 2 good places.
Melbourne - Best night life in Melbourne clubbing/bars, Pretty big with automotive, Not to expensive living for example im from melbourne and i live 20minutes from the CBD but housing is cheap here for rent you would be looking at $200ish for a 3bedroom house.
I guess the best way to find your "place" in Australia is to do your research
