Who was our worst Prime Minister and why? Any notable state leaders we need to add?

I'd say the entire Abbott/Turnbull/Morrison trifecta was terrible.

Abbott was definitely out of his depth as PM, he never stopped being the leader of the opposition and was always pugilistic, impulsive and didn't think things through. He promised stable leadership but didn't have his party under enough control to ensure it - probably because he sort of skated into the role because those who the party actually wanted didn't make it. He got into power on the back of a campaign focused on debt and deficit, but had no policies to address it and I don't think he ever intended to. He played his pet issues but was aggressively ineffective at everything else.

Turnbull was a devastating disappointment. Hated by his own party, only used as a more popular and sensible replacement for the ousted Abbott, but never having any party backing for his agenda. I'd say he flamed out, but he was never even on fire. Reneged on his promises and ambitions for fear of reprisals from his party - a spineless creature whose years in power were an absolute waste and a net loss for the country.

And then of course Morrison. A sociopath who bradbury'd into the role because enough people in the party room had the self-awareness to realise Dutton as party leader would be a disaster. Obviously Morrison schemed his way through that entire leadership crisis and lied whenever he opened his mouth, not least when professing his support for the embattled Turnbull. He was probably the most useless PM, out of the country in times of crisis and actively refusing to show leadership. Not to mention the shameful mishandling of the pandemic.

Collectively these three set back social, economic and political development in this country back by at least a decade. We're all worse off thanks to the nine years of having these three clowns in power.