Buy a nice freestanding house. Rent out my apartment. It's what makes the most sense for me since that is the next big financial commitment I wish to make, and the savings in bond interest is as good as an investment. Apart from the rental income from my apartment, and the hopefully inevitable increase in value from the new property.
I'd say that would equate to an effective 10-20%pa return for a long time.
For me it is more due to how much I can save by being able to buy a house cash. Prime is low right now, but you'll still end up paying about double the value of your home if you go for a bond over 20 years. That matters in this equation. If I were to get the bond AND use the 2 million to invest in something great that can give 10%+ returns with low risk, then I'd still be effectively netting savings account-like returns all things said and done.
Far better to start square and then just rent out my apartment. Although I'll be the first to say that things leaning towards rather selling the apartment with new sectional title laws just around the corner. It's already a story to buy to rent as an investment. So the point might be moot.