The latest version:
AUSTRALIAWHAT
0. Pay the minimum required on all debts.
1. Establish an emergency fund to your satisfaction. See
https://www.bogleheads.org/wiki/Emergency_fund. Use your mortgage offset account OR use springy debt
http://www.mrmoneymustache.com/2011/04/22/springy-debt-instead-of-a-cash-cushion/ .
2. Pay off any debts with interest rates above your mortgage rate (if you have one)
3. Put money into your PPOR mortgage offset account (if you have one).
4. If your taxable income is less than $51,021 (before salary sacrifice) consider contributing $1000 per year to superannuation to get the Government co-contribution.
5. Pay off any debts above the return you can get on your investments.
6. If you taxable income is more than $37,000 optimise Salary Sacrifice into Superannuation - you need to work this out individually, because how much depends on at what age you will ER, how much is already inside/outside superannuation, and your marginal tax rate.
7. Invest any extra into low cost index funds (long term investments - 10 years) or high interest accounts (short term - 2 or 3 years).
WHY
0. Don't get yourself into trouble.
1. Give yourself at least enough buffer to avoid worries about paying bills.
2.& 3. Because it's untaxed, the effective return on a mortgage offset account is likely to be the highest percent return you can get on your money
4. When the government is giving you money - take it.
5. It's better to pay off expensive debt than to invest.
6. Salary sacrifice is taxed at 15% as it goes into superannuation and people on low incomes have a lower tax rate. You will need other money to last you between when you retire and when you are eligible for superannuation. However superannuation tax rates are low.
7. Because earnings, even if taxed, are beneficial. If you are saving for the short term (eg. a house deposit whether PPOR or IP), you want to be absolutely sure that you will get back what you saved, but longer term savings are better off in an index fund.
Note: This assumes that you are employed. If you are a business, make sure that you put the 9.5% superannuation guarantee for yourself because if the business fails, you will at least have that money in old age.