This.

Killing populism: What Australia has to teach Britain

I remember hearing about preferential voting and how it worked when I lived in Australia in the 90s. I couldn't articulate why I thought it was a good idea then, but I think it was because you really should think about your preferences, rather than just sticking a cross in a box.

(At that point, I had never voted in any sort of election, as my home address was always located in a safe seat that went unopposed.)