I use Nabtrade IRESS - personally I think it is rubbish. Crashing and also no chi x.
Commsec IRESS seems popular with a few on the DT threads but some have issues with it playing up and its expensive.
Mitta uses FPmarkets IRESS and likes it, but doesn't have chi x or you have to pay extra for it.
ETrade is obviously teething for some people.
CMC is cheap and the charting is good but doesn't have options nor chi x
There is no perfect one!! They're all a mixture, just have a play around. I am trialling the IB demo on their website, love it but haven't traded with it yet as I want to familiarise myself with it first.
Goodluck with your choice