Well...that depends on what type and where...There are many very nice restaurants of all types in major cities. It's been a number of years so I can't specify by name but Oz is very heavily influenced by the Asian/Thai culture as well as heavily Italian.
There was a "Lone Star" (an upside down "Outback") in Adelaide that was excellent and we went there often. I'm certain you can find outstanding steakhouses there as well. OH, a place on the Goldcoast...well, inland from the Goldcoast. It's a steakhouse and it's outstanding. If you are heading to that area let me know and I can go through my stuff and find the name. (assuming they are still there) Unbelievably wonderful, brilliantly prepared and plentiful food. An app was avocado with caviar, capers, salmon, red onion, toast...it got my daughter hooked on caviar at age 8.
The "Chinatown" area of Sydney has many excellent restaurants as well.
<Pie floaters? Pasties maybe? ...LOL>
Things that are great: Pumpkin soup and Salt and Pepper Squid. Thai anything. Lamb dishes.
Don't expect to find remarkable Mexican food.
Hamburgers with "everything" will have just that. Pineapple, egg, beetroot, bacon (which is actually more like Canadian bacon), cheese, tomato...etc etc...
Ok, before I continue, where are you going?