Aussie Broadband is not the cheapest, but it is by far the best I've used. They have consistently good speeds, knowledgeable customer service, and even offer a pro rata refund when cancelling.
Dodo tried to charge me an illegal fee and would hang up when I tried to dispute it. I told them I would take it to the ombudsman then hung up on them. A supervisor called back withing 10 seconds to offer to remove the fee and provide a refund for the last 3 months. They knew what they were doing was illegal.