Visited a few over the years.

I'd say the most impressive, in terms of breath taking beauty have been Uluru, Steep Point and Coles Bay.

The Chinese love a place outside of Melbs called Lake Tyrrell - never heard of it.

There are tons of hidden gems.

Rockingham.

Uluru yes,

..and hidden gems like Pine Gap could be another kind of impressive

Watarrka National Park. Purnululu National Park, Karijini National Park, Uluru-Kata Tjuta National Park, Blue Mountains World Heritage Area.

This is my wallpaper at the moment, not a high quality pic but Mitchell Falls by moonlight is something special.