Just a few km North of Mt Samaria State Park was where I've ever seen the deepest. And I've travelled far and wide in search of dark skies over the past 10 years. I spent a lot of time under the night sky almost everywhere in Victoria and also North of the border in NSW. Mt Samaria SP was the best in my experience. (There is free camping in the park as well.) I've never seen the Milky Way sparkle so and the dust lanes so detailed and distinct. It was a clear winter night. I was so impressed that I was compelled to post about it at the time:
http://www.iceinspace.com.au/forum/s...ad.php?t=12639
The skies have degraded since. It's mostly not due to light pollution but changing climate. Summer skies in Victoria are becoming more and more humid (sub-tropical like) which reduces transparency. Winter skies have fewer clear nights (than summer nights) but when it's clear in winter it's likely to be better than any clear summer night.