I voted for The Vivisector by Patrick White in the Australian Book Review survey of favourite Australian novels. It made it into the Top 20 at place 14.
The book is also in the running for the 1970 Lost Man Booker Prize. That year, the rules were changed and 1970 books were not considered. The prize is now being reconsidered. Would Paddy have cared? (Probably -- he was a dark horse.)
If you are frightened of reading Paddy and who isn't, The Vivisector is a good place to start. It's a very Sydney novel. I'm thinking of the humidity and dampness there at the moment and the book's atmosphere is already with me. I like to think it is close to being a self-portrait -- the cruelness of the artist cutting through emotional sinews in pursuit of his obsessions.