Cheapest gigabit plan according to Gizmodo.
If you’re keen to jump on the highest speed NBN train, Kogan’s NBN 1000 plan is currently on sale for $134.90/month for your first six months. That makes it the cheapest NBN 1000 plan available on the market right now. After that it will go up to $148.90/month.
If you don’t need to go quite that hard, Kogan has also introduced NBN 250 plans to its lineup. At the moment it is offering $116.90/month for your first six months, and $128.90/month thereafter.
Internode has been average ever since it got bought out. The ex-internode staff started their own ISP called Aussie Broadband, it's pretty well regarded.