Kathryn Schulz offers her list of the greatest punctuation marks in literature, and it is a wonderful one.

3. The ellipses in T.S. Eliot’s “The Love Song of J. Alfred Prufrock”
Let us go, through certain half-deserted streets,
The muttering retreats
Of restless nights in one-night cheap hotels
And sawdust restaurants with oyster shells:
Streets that follow like a tedious argument
Of insidious intent
To lead you to an overwhelming question …
Oh, do not ask, “What is it?”
Let us go, and make our visit.
Okay, I concede: The most famous ellipses of all time is not in "Prufrock." It is not in literature at all. It is in the text crawl at the beginning of Star Wars (“A long time ago in a galaxy far, far away …”), which I can’t read without hearing that crashing first chord of John Williams’s score, and which I admire even while wishing George Lucas had seen fit to include one more comma.
But we are here to talk about literature, and, in that domain, Eliot wins the ellipses game. Everything in "Prufrock" is elliptical: those meandering streets, the foglike cat (fog and cats: name me two things more evasive), the hundred revisions, the perfume-inspired digressions — and all this is to say nothing of the five other literal ellipses in the poem: “lonely men in shirt sleeves, leaning out of windows … ”; “asleep … tired … or it malingers”’ “I grow old … I grow old … ” — aging in those very pauses, it seems. But by far the most yawning chasm in the poem is the first one: What overwhelming question, Eliot? The candidate options, as I see it, are “What is the meaning of life?” and “Hey, so, would you maybe want to have dinner with me sometime?” Existential exposure, romantic embarrassment: Poor Prufrock, no wonder he trails off into that visual stutter.