I've been thinking this for almost all my life: the voting systems used in almost every country are plain ridiculous. The only country I know that uses a system that sounds reasonable is Australia.
https://www.youtube.com/watch?v=l8XOZJkozfI
Closer to home, it's also used by the Apache Software Foundation for the annual election of the Board of Directors.
When the election is only for a single position, this is exactly equivalent to "instant runoff".
For the House of Representatives, each electorate is much smaller and parties only have one candidate each, so you only have five or six choices, and you preference all of them.
1. https://www.smh.com.au/content/dam/images/z/r/7/i/p/image.re... 2. http://farm8.static.flickr.com/7296/9569414534_b3ee06fd84.jp...
It's okay IMO but could be improved somewhat.
The Open List system used in most of Europe (with France, parts of Germany, and Spanish congress being notable exceptions) seems like a very good, successful one also.
UK is still first past the post for MPs. Australia seems to be different again but not first past the post.
When there are is only one winner and STV is exactly the same as instant runoff, it is not so difficult to understand.
This surprised me but you're right. NI have(/had?) STV, but not Westminster. Very odd.
> Australia seems to be different again
This was my question really. Australia uses IRV, afaik, which is somewhat equivalent to STV except that it's slightly simpler, though I don't see any major disadvantage to the extra complexities in STV.