Bathurst, of course! Although it is really one of two (permanent) circuits in Australia up to international standards, the other being Phillip Island. The rest of the circuits down here are produce some pretty good races but for the most part I occasionally feel like our top racing series' are close to outgrowing them. But with that said I don't feel like our top series should be racing on F1 grade circuits, the V8 Supercar races in Abu Dhabi, Bahrain, China and Austin have all been pretty dull compared to the races at home.
Australia does have a good collection of street circuits, for sure. I've attended the Clipsal 500 at the Adelaide Street Circuit every year since 2003 and I absolutely love it. The track produces fantastic races every year, the facilities do leave a little bit to be desired but it's always great for the fans, with lots of general admission viewing areas (especially for a street circuit) with a decent view and shade. Albert Park is fantastic too, although I haven't actually been there, but even as a South Australian I can say that it deserves F1 much more than Adelaide!