Although he visited Australia several times, I never saw Luciano in person, though I have heard his magnificent voice on CD. My favourite is his portrayal of the Duke in the 1971 Rigoletto with Joan Sutherland conducted by Richard Bonynge. If you get a chance to listen to it (my version is Decca 414 269 - 2) do so. If you're not accustomed to listening to whole operas, try "Questa o quella..." (CD1 track 3). If you don't agree that operatic singing doesn't (cannot?) get much better than this I'd like to know. Oh, and Ms Sutherland is very good, too.
There are many tributes and obituaries online, for example this from The Times, which has links to some recordings and videos.