Internode is by far the best. But not the cheapest, they do offer a great range of umeated content (not including usernet, but is free to use)
iiNet would be second on that list, another great ISP
TPG and Adam aint that bad either
Also some allow you to use your quota anytime, others have peak and off peak.
The problem is those that offer peak/off peak is . They say look we offer 150GB of data but looking at the peak 75GB / off peak 75GB. But then look at the times, usually the off peak is late and only a few hours long. So you'll never use the total off peak quota.