http://www.time.com/time/2005/100books/the_complete_list.html
seems pretty good to me. at least a fifth of those authors are the greatest we've ever seen.
orwells, waughs, millers, pynchons (?), nabokovs, faulkners, woolfs.
beckett, too. of course this also excludes almost all philosophers. camus? i wouldnt go by books. if you hear about a greatest author read their least-known or first-written book. i think they're always a lot more telling. crome yellow, anyone? a happy death? burmese days?