I am not a hat fan, never will be, but Qantas/Qantaslink still have them. Tiger does not have hats, they have the traditional jacket/tie which is navy in colour. Jetstar are pretty much the same although from memory they have a set of wings imprinted on the jacket, and is more black in colour.
LCC's dont seem to be huge on the hats, but airlines like AirAsia seem to still employ them.