If you were to ask me that question, several novels would immediately spring to mind. I suppose I have read quite a few more than once, but not so many more than three times.
Le Rouge et le Noir
The one novel stands out as the obvious answer for me is "Scarlet and Black," by Stendhal, which I suppose I have read at least four times by now.
My first encounter with the novel was in my second year at university. It was a set text in a course I was taking, most likely "Politics and the Novel."
I am ashamed to admit that my first hasty impressions of the novel were not favourable! I remember ranting to a friend about why the novelist was spending so much time introducing us to some dreary French town of no interest to man or beast.
Ahem, such is the foolishness of youth, but, to my credit, if I may blow my own trumpet, I quickly warmed to the main character, Julien, his intelligence, his sense that life was something to be grasped, his idealism, his facility for feigning piety, a most convenient skill to aquire both then and now; but most particularly, I admired him for pursuing his campaign to seduce Madame de Rênal, which seemed - seems - a thoroughly laudable quest upon which to test a young chap's mettle.
Other Novels I've Read At Least Three Times
The Great Gatsby, by Scott Fitzgerald - and I am about to read it for the fourth or fifth time.
A Passage to India, by E. M. Forster
The Secret Agent, by Joseph Conrad
Orlando, by Virginia Woolf
What are your favourite novels? Are there any that you have read three or more times? Let me know in the comments, below!