In NSW the unit trust would need to be classed as a "fixed trust" to qualify for Land Tax Threshold. Not all unit trusts are fixed.
Coasty is right though, Tax exempt Charities must be the greatest structure.
Imagine you set up your own little religious group - philosophical questions aside. You buy a nice little property, no stamp duty or land tax, you may even receive some grants. Discounts on rates, maybe no rates at all. To buy the property devotees make tax deductible donations to the body so the individuals benefit in saving tax too. You then have the property closed for use of the general public and only for members of your little group. The average person cannot claim a deduction for many things, but they can claim a deduction for donations to the body who can then provide these things to the individual. eg. Childcare.