Canberra! Its not for everyone but it is a great place to raise a family and being a government town has good employment prospects, flexibility and salary level. A big country town with access to some of the best little disturbed coastline in Australia only 2 hours away (we love to surf). Great bike path system a lot of it off road. While its a conservative town in many ways we also had the biggest Green vote in Australia. Also Sydney is only 3 hours away if you want the breath of arts and culture that may not come as far as Canberra.
I left Brisbane 10 years ago and now find it very busy/road centric and hard to get across town. Also too sticky for me, I like drier heat these days. The sprawl is incredible too.
Sydney I wouldn't ever consider, Adelaide, Darwin and Perth are too far away from our families.
Melbourne I do like although I find it dirty (sorry Lime) compared to Canberra and Brisbane. But with the climate changing over the next couple of decades Melbourne is less likely to be as drizzly and grey and would be my second choice for a city to live in as long as it wasn't too far out from town. The sprawl goes on and on in all directions.