Australia Zoo is probably one of my favorite places to visit here on the sunshine Coast, the animals are treated well and they have plenty of space to roam and do their own thing. They also do a lot of good for Australian wildlife, not so long ago they even came to rescue an injured Roo that was sitting in my front yard.
My second favorite Zoo though would have to be Taronga Western Plains Zoo which is near Dubbo in New South Wales.
It is a completely different experience and the place is huge, you can drive around or take a bike and enjoy the animals at your own pace. Just be sure to dedicate a whole day for the experience.