I suppose it depends how good you are and where you live. I am about a 25 handicapper so an average hacker. The hardest I have played over here is Secret Harbour and Port Kennedy when it is windy. The best was probably the Cut but again that is very hard.
Local to me: Maylands - average and can get very busy
Atlone - solid little nine hole and cheap
Hillview - 3 separate nine hole courses, affordable and you can get on
Whaleback - average, quite expensive and can get packed