There is no official statistics to give a definite answer to the question. According to the survey conducted by the Property Council of Australia in 2011 , Adelaide is the best city to live in Australia in terms of outdoor recreation, schools, public transport, house prices, natural environment and etc. According to Monocle's Most Livable Cities Index 2011, Melbourne and Sydney are the two most livable cities in Australia. However, the index does not take consideration of the cost of living.

If you want to move to Australia and don't know which city to live. This article may give you some ideas.