“I lingered round them, under that benign sky: watched the moths fluttering among the heath and harebells, listened to the soft wind breathing through the grass, and wondered how any one could ever imagine unquiet slumbers for the sleepers in that quiet earth.”
-Emily Bronte, Wuthering Heights
Isaac Asimov’s The Last Question
He said “Let there be Light” and there was light.
“please if you get a chanse put some flowrs on Algernons grave in the bak yard…”
Flowers for Algernon - Daniel Keyes
Si
“And I walked back to the hotel in the rain.” – Ernest Hemingway, A Farewell to Arms
Hoo, yeh, that’s another one that really got to me.
"When I saw her out there in the hallway I knew she was no mulatto. And those distorted features still reflect a family likeness. I’ve seen her portrait, and I can’t be mistaken.
There lies the creature that was once Celia Blassenville."
Pigeons from Hell - Robert E. Howard
“When I speak of poor Norrys they accuse me of this hideous thing, but they must know that I did not do it. They must know it was the rats; the slithering scurrying rats whose scampering will never let me sleep; the daemon rats that race behind the padding in this room and beckon me down to greater horrors than I have ever known; the rats they can never hear; the rats, the rats in the walls.” – H.P. Lovecraft
“It’s a cookbook!” – Damon Knight
Sorry, I’ll have to post a whole paragraph.
Senor Catfish got it right. Nitpickily, it’s All Quiet on the Western Front (title and last words.) And read the book before the final sentence, or it ruins it.
Final two sentences of The Haunting of Hill House:
Hill House itself, not sane, stood against its hills, holding darkness within; it had stood so for eighty years and might stand for eighty more. Within, its walls continued upright, bricks met neatly, floors were firm, and doors were sensibly shut; silence lay steadily against the wood and stone of Hill House, and whatever walked there, walked alone.
“The creatures looked from pig to man, and from man to pig, and from pig to man again; but already it was impossible to say which was which.” --Animal Farm
You beat me to Fitzgerald’s Gatsby. Love that line.
“…and whatever walks there, walks alone.”
A reprise of the first paragraph of the book, The Haunting of Hill House, by Shirley Jackson. As Stephen King says and I paraphrase, if the blighted place wasn’t haunted in the beginning, it most certainly is by the end.
God, I love that book. Scariest, subtlest “fast read” in existence, IMHO.
Beat you by 3 posts, Rebecca. I love that book too, and I knew I was going to after reading only the first paragraph.
The last lines from The Brothers Karamazov, always been one of my favorite books and the last line has stuck in my memory since I first read the book six years ago.
The lines come after an impassioned speech by Alyosha Karamazov at the funeral of a young boy who was a representation of the authors own son who had died at the age of three while he was writting the book.
Seconded. 
The last paragraph of Heinlein’s classic short story “The Man Who Traveled in Elephants” will make your eyes blurry, unless you’re a Vulcan.
HPL loved his last lines! So much so that it lends itself to parody. I have a book in storage, Shaggy B.E.M. Stories, which is an anthology of parody SF. It includes a chapter on “M.M. Moamrath,” an HPL parody described as “SF’s answer to P.D.Q. Bach.” From “The Commonplace Book of M.M. Moamrath,” which is a collection of nothing but last lines around which Moamrath intended to construct a story:
"No, Krautmord, I will be unable to attend this year’s Wurstfest. You see, I have been dead for three years!"
"And the last thing I saw as the horror stood over me was the horror . . . standing over me!"
“'Ho ho, he he, my name is P’inkhi-li!’ the thing gibbered.”
"And there on the floor was nothing but a pair of boots, and sticking out of them – the protruding tibias of Elmo Freebish!"
Since Peter Morris beat me to “The Last Question”, I’ll submit a different Asimov:
[spoiler]Statis was punctured and the room was empty
from “The Ugly Little Boy”[/spoiler]
I know the OP didn’t mention movies, but can anything top “Louis, I think this is the beginning of a beautiful friendship”?
Sure.
“Oh, no. It wasn’t the airplanes. 'Twas beauty killed the beast.”
And, even better:
Kitty: I was reading a book the other day.
Carlotta: Reading a book?
Kitty: Yes. It’s all about civilization or something. A nutty kind of a book. Do you know that the guy says that machinery is going to take the place of every profession?
Carlotta: Oh, my dear, that’s something you need never worry about.