One wild success, or a career of pretty good?

Would you rather write one insanely successful book, or a string of literary titles? I would take the one-off (less work, my friends), but there's been some discussion about which is better:

Sometimes, there are writers who seem born to produce just one book. Ralph Ellison published Invisible Man in 1952 and spent the rest of his life trying to follow it. Malcolm Lowry's Under the Volcano was the fruit of a life-and-death struggle. Jack Kerouac's On the Road towers above all his other books, and he died an alcoholic aged 47. Guiseppe di Lampedusa's The Leopard was not fully recognised until after his death.

Either way, in songs or novels, sustaining a lifetime's work as a writer is exceedingly difficult. Most literary careers begin, and possibly end, before the age of 40. Some fly too close to the sun, and fall to earth; others give up, exhausted and demoralised.