20 to 1 Best Aussie Song

I watched the show 20 to 1 last night on Channel 9, it was about the top 20 songs in Australian music of all time. It was fun to listen to some of the songs that came out of my high school era (late 1980's, early 90's) but I was surprised at their number one choice which was 'Friday on my mind' by the Easybeats. I guess it's not something I grew up with or a song from my generation. I'd heard it plenty of times before but it wouldn't have been my number one choice. I was pretty pleased that great Aussie songs such as 'Great Southern Land' by Icehouse and 'Land down under' by Men at work made it into the top 20. Those songs are such great Aussie icons. Which song would you have put as the top all time best Aussie song?