I am with RACQ and have always found them great to deal with - had one claim without any issues in them paying. I have a almost 3 year old 4 cylinder car and pay around $40/month - it is cheaper if you pay for the full year in advance though by about 6% I think it is.

AAMI have always been close toe twice the price when I've got a quote from them in the past - I think it really depends on what state you're in. I always do online quotes at a number of different places when the insurance comes due.