I scoured the Internet (and my memory) for some well-known last words of famous people. Not all of these are literally the last words the person ever spoke, but they are alleged to be among the person's final communications. A lot of urban legends have sprung up about deathbed quotations, and it's possible that some of these quotes are made up or embellished. Where I'm aware of a discrepancy, I've noted it.
"Crito, I owe a cock to Asclepius; will you remember to pay the debt?" – Socrates just before drinking hemlock. This quote is often misunderstood as an example of Socrates making a trivial, homely allusion immediately prior to his death. Actually, he was making a reference to the practice of donating a cock (= rooster) to the god of healing, Asclepius, after one had been cured of an illness. The implication is that life is the illness which death will cure. The quotation appears in Plato's work Phaedo, and may or may not be historically accurate.
"Thomas Jefferson ..." - John Adams. This quote is often rendered as "Thomas Jefferson survives," or in similar words. But it seems that only the name Thomas Jefferson was distinctly heard by the people at Adams's bedside. Adams and Jefferson had become friends in their old age, though they had been rivals earlier. It is usually assumed that Adams meant to say that Jefferson was still alive even as he lay dying (though in fact Jefferson had died a few hours earlier). An alternative explanation is that Adams had a deathbed vision of the newly deceased Jefferson waiting for him on the "other side."
"It is very beautiful over there." – Thomas Edison. According to Wikiquote, "These have sometimes been reported as his last words, but were actually spoken several days before his death, as he awoke from a nap, gazing upwards, as reported by his physician Dr. Hubert S. Howe, in Thomas A. Edison, Benefactor of Mankind : The Romantic Life Story of the World's Greatest Inventor (1931) by Francis Trevelyan Miller, Ch. 25 : Edison's Views on Life — His Philosophy and Religion, p. 295."
"Turn up the lights, I don't want to go home in the dark." – O. Henry, quoting a popular song of his day.
"I see black light" – Victor Hugo.
"Curtain! Fast music! Light! Ready for the last finale! Great! The show looks good, the show looks good!" – Florenz Ziegfeld, the legendary showman and creator of the Ziegfeld Follies. This quote is often given, but seems to be considerably embellished. However, it does appear to be true that Ziegfeld died giving stage directions and that his last words were something like, "Looks good! Looks good!"
"You're right. It's time. I love you all." – Michael Landon, the American TV star, after his family had gathered around him and his son had told him it was time to move on. These do not seem to have been literally his last words, but he spoke them only a few hours before he died. He is said to have been alone with his wife Cindy at the moment of passing, and his actual last words were "I love you."
"A certain butterfly is already on the wing." – Vladimir Nabokov, author of Lolita. Nabokov was a great butterfly enthusiast. Although this could certainly be a reference to the liberation of the soul from the body, it could also refer to an actual butterfly that Nabokov had been chasing and which had eluded him. Possibly it means both things.
"This is all an elaborate hoax." – Roger Ebert, in a note to his wife on the day before his death.
"Oh wow. Oh wow. Oh wow." – Steve Jobs' last words, according to his sister Mona Simpson. There is also an Internet story that has gone viral on social media claiming that Jobs' last words were an elaborate rejection of materialism and worldly success, but this claim has been thoroughly debunked.
"Let us cross over the river and rest under the shade of the trees." – Gen. "Stonewall" Jackson, after being shot by one of his own men.
"I've got to get to the top of the hill." – Financier J.P. Morgan.
"I can't see a damned thing." – lawman Morgan Earp to his brother, Wyatt Earp. They had promised each other to report any vision of the next life if they had the chance.
And finally this example of understated heroism from the explorer Robert Scott, whose Antarctic expedition ended in tragedy when the entire team froze to death. These words were found in Scott's diary, though they were not the very last entry:
"We are weak, writing is difficult, but for my own sake I do not regret this journey, which has shown that Englishmen can endure hardships, help one another, and meet death with as great a fortitude as ever in the past. We took risks, we knew we took them; things have come out against us, and therefore we have no cause for complaint, but bow to the will of Providence, determined still to do our best to the last."