Talking of names that haven't been used for a while, here's some below:
* Bataan - Tribal Class Destroyer (sister of Arunta and Warramunga)
* Napier, Nepal (ex Norseman), Nestor, Nizam - N Class Destroyers (the other N Class, Norman, is currently one of the Huon Class Minehunters).
* Quadrant, Quality, Queenborough, Quiberon, Quickmatch - Q Class Destroyers (later converted to anti-submarine frigates).
* Vampire, Vendetta Voyager, Duchess - Daring Class Destroyers (already mentioned).
* Barcoo, Barwon, Lachlan, Macquarie - River Class Frigates (some other names of that class are currently in use for the Huon Class Minehunters).
* Condamine, Culgoa, Murchison, Shoalhaven - Bay Class Frigates
* Warrego - Grimsby Class Sloop (sisters were, Yarra, Parramatta and Swan).
Anyway, there's some examples of currently unused names.