
Nobody knows why, but many choose Melbourne as the preferred city to live.
As you can see in the map (Above)
Melbourne is in the state called Victoria, Adelaide is in South Australia, Sydney is in New South Wales.
All these main cities have good Universities. But you have to think and identify your priorities in life before choosing a University in Australia.
If you want to have a life with full of 'fun' then better choose Sydney or Melbourne. But if you need a peaceful and a quiet life, then it should be Adelaide without any doubt.
Cost wise, Adelaide -> Melbourne -> Sydney in ascending order ;)
As a whole, the quality of Education is almost the same in all the cities even though there might be few minor differences.