Melbourne's concept is a very good one because it gives us the best idea of what a city looks like that retained it's almost ill-fated Tram network. (Sydney has learnt the hard way, as is Adelaide, in fact, most Australian cities are!)
Trams are the best solution for an inner-suburban Transport network, with buses providing the outer-suburban services. Heavy Rail, meanwhile, is the best of both worlds, and where heavy rail can't be applied or built then the above two options are obviously looked at.
Hence why I would have a mostly restored Adelaide Tram Network replacing most of the inner-suburban bus routes. That is, in my perfect world
. These include, in clockwise order from the NW Suburbs:
Cheltenham/St. Clair (Torrens Road)
Blair Athol/Enfield/Prospect (Prospect Road, via North Adelaide)
Oakden/Walkerville (North East Road then Fosters Road)
Magill (Magill Road)
Norwood/Kesington Gardens (The Parade)
Erindale/Kesington/Toorak Gardens (Kesington Road)
Burnside/Hazelwood Park (Greenhill Road)
Springfield (Fullarton Road)
Unley/Unley Park/Hawthorn (Unley Road/Belair Road)
Hyde Park (King William Road)
Colonel Light Gardens (Goodwood Road)
Richmond (Richmond Road via Anzac Highway and West Terrace)
West Beach (Sir Donald Bradman Drive/Burbridge Road)
Henley Beach (Henley Beach Road)
Feel Free to add others to that list.