Which is the best AOG church in the Myrtle Bank area?

Did you mean an everyday Anglican Church? There are several to choose from. Saint Augustines on Unley Road is lovely, well supported and I often notice weddings happening there when I am shopping in Unley

OR did you mean the Anglican spin off - namely one of the AOC (Anglican Orthodox )

AOC: The Anglican Orthodox Church was founded in 1963 by Bishop James Parker Dees. Over the decades there have been several divisions of the church resulting in the need to reincorporate in 1999. The church was then re-incorporated once again as an international church in 2001 to allow for its international churches abroad to be legally included as entities of the Anglican Orthodox Church.[1] Bishop Dees left the Episcopal Church due to what he believed were its immoral policies and doctrinal errors. In so doing, he acted about a decade and a half before a larger number of conservative Episcopalians separated from the Episcopal Church following the decision of its general convention to approve the ordination of women as priests. The AOC today preserves the traditions of Dees and has national church affiliates in 22 countries around the world.

OR

Did you mean the AOG (Assemblies of God)
I have no ideas where the Assemblies of God Churches are in Adelaide - contact your own local AOG and the administrators there should be able to advise you re where to find them in Adelaide.