I have been using Exetel for a couple of years now. Why do I think they are great?

1. The most cost effective ISP in Australia - AFAIK
2. A fixed IP on your DSL connection means you can have your own web presence without having to resort to dynamic dns
3. The notification emails actually tell you exactly what went wrong and what they are doing / did to fix it
4. Even when they got shafted by a supplier they got everyone re-connected and made good on it (my mother included)

I'm not sure if they have a fancy Telstra style installation CD and as far as I can remember I've never used the helpdesk except to enquire about an outage. So I can't speak authoritatively on that part of the service.

However if you want a cost effective ISP then give Exetel a go.