For a very peaceful but decadent birthday, I was surprised by the Matilda Bay Restaurant. The service was exceptional and the food really was sublime. The restaurant is set up in sections so you can choose a booth or a table. And they spoil you when desert come out!!
Going out anywhere on your birthday can be special.... There are some great birthday offers at the Crown casino complex eg free wine, and there's some lovely choices. The C restaurant can be very special too. Hippo Creek is a nice place to spend a birthday and also the Subi Hotel.