Many types of insurance are offered by financial institutions.
Some types of insurance to be covered here:
InsuranceWatch is a service that compares insurance products in Australia (link) and contains some useful information.
Known auto insurers: aami (recommendation from an expat forum), racv.
To read GMHBA-related posts on Australian blog, click here. There are some interesting details available there, as well.
iSelect (link) used to be a service for finding and comparing different private health insurance offers from providers. It provides information from only the funds that chose to participate.