Epitaphs are the inscriptions on headstones.

As many epitaphs are not written by the person who is being honoured, the format shall be as follows:
Honouree (by author) - Year of birth - Year of Death
Text of Epitaph
More explanation text

Sorted alphabetically by lastname.

A
John Quincy Adams (by himself) - 1767 - 1848
"This is the last of Earth! I am content!"
Alexander the Great (unknown) -
"A tomb now suffices him for whom the world was not enough"
Gracie Allen and George Burns (themselves) -
"Together again."
Duane Allman (unknown) -
"I love being alive and will be the best man I possibly can. I will take love wherever I find it and offer it to everyone who will take it. I will seek knowledge from those wiser and teach those who wish to learn from me."
Andre-Marie Ampère (unknown) -
"Tandem Felix (Happy at Last)"
Susan B. Anthony (unknown) -
"Liberty, Humanity, Justice, Equality"

B
Nick Barnard (not actually dead, obviously) -
"Beloved wife and mother"
Jakob Bernoulli (by himself) - 1654 - 1705
"Eadem mutata resurgo"
Though changed I shall arise the same
Referring to the accompanying inscription of a logarithmic spiral, which remains the same after mathematical transformations. He considered it a symbol of ressurrection. CLARIFICATION: Bernoulli called the logarithmis spiral Spira mirabilis, "the marvelous spiral", and wanted one engraved on his headstone. Unfortunately, an Archimedean spiral was placed there instead.
Billy the Kid (unknown) -
"Truth and History.
21 Men.
The Boy Bandit King
He Died As He Lived
William H. Bonney 'Billy the Kid'"
Mel Blanc (by himself) -
"That's all, folks!"
William Bligh (unknown) -
"Sacred
To The Memory Of
William Bligh, Esquire F.R.S.
Vice Admiral Of The Blue,
The Celebrated Navigator
Who First Transplanted The Breadfruit Tree
From Otahette To The West Indies,
Bravely fought The Battles Of His Country
And Died Beloved, Respected, And Lamented
On The 7th Day Of December, 1817
Aged 64"
Edmund Blackadder (by himself)
"Here lies Edmund Blackadder, and he's bloody annoyed."
Charles Bukowski (by himself)
"Don't Try"
Samuel Butler (by Samuel Wesley) - 1612 - 1680
"While Butler, needy wretch, was yet alive,
No generous patron would a dinner give;
See him, when starv'd to death, and turn'd to dust,
Presented with a monumental bust.
The poet's fate is here in emblem shown,
He ask'd for bread, and he received a stone."

C
Adrian D. Canfield (not dead) -
Adrian D. Canfield, the bluntest, most straightforward man all the way to the end. May he rest in peace knowing that sexists are right in their beliefs.
Al Capone (by himself) -
"My Jesus, mercy"
George Washington Carver -
"He could have added fortune to fame, but caring for neither, he found happiness and honor in being helpful to the world."
Winston Churchill
I am ready to meet my Maker.
Whether my Maker is prepared for the great ordeal of meeting me is another matter.
Samuel Taylor Coleridge (by himself) -
"Stop, Christian Passer-by! - Stop, child of God,
And read with gentle breast. Beneath this sod
A poet lies, or that which once seem'd he. -
O, lift one thought in prayer for S.T.C.;
That he who many a year with toil of breath
Found death in life, may here find life in death!
Mercy for praise - to be forgiven for fame
He ask'd, and hoped, through Christ. Do thou the same!"
Robert Crawshay (unknown) - b 1817 d 1879
"God forgive me"
Robert Crawshay of Cyfarthfa, South Wales, the last of four generations of wealthy iron-masters; much hated in his lifetime and afterwards for his refusal to accept the increasing unionisation of his workforce. Buried under an 11 ton granite slab in Vaynor churchyard, these words are the only inscription on the tomb.
Ian Curtis
"Love Will Tear Us Apart"
Singer/Songwriter of the band Joy Division

D
Bette Davis (unknown) -
"She did it the hard way"
Jefferson Davis (unknown) -
"At Rest
An American Soldier
And Defender of the Constitution"
Emily Dickinson (herself) -
"Called back"
Arthur Conan Doyle -
"Steel-true and blade-straight
The great artificer
Made my mate."
Diophantus of Alexandria -
"This tomb hold Diophantus. Ah, what a marvel! And the tomb tells scientifically the measure of his life. God vouchsafed that he should be a boy for the sixth part of his life; when a twelfth was added, his cheeks acquired a beard; He kindled for him the light of marriage after a seventh, and in the fifth year after his marriage He granted him a son. Alas! late-begotten and miserable child, when he had reached the measure of half his father's life, the chill grave took him. After consoling his grief by this science of numbers for four years, he reached the end of his life."

E
Wyatt Earp
Nothing's So Sacred As Honor
And
Nothing's So Sacred As Love.
Emmet Robert 1778-1803
"Let no man write my epitaph; for as no man who knows my motives dare now vindicate them, let not prejudice or ignorance asperse them. Let them and me repose in obscurity and peace, and my tomb remain uninscribed, until other times, and other men, can do justice to my character; when my country takes her place among the nations of the earth, then, and not till then, let my epitaph be written. I have done."
Edward I of England
Edward I
"Hic est Edwardvs Primus Scottorum Malleus"
" Here is Edward I, Hammer of the Scots"

F
W.C. Fields (unknown) -
"W. C. Fields 1880 - 1946"
In a 1925 article in Vanity Fair Fields had proposed the epitaph "Here lies W.C. Fields. I would rather be living in Philadelphia." because of his long-standing jokes about Philadelphia, and the grave being one place he might actually not prefer to be (he was actually born there). This is often repeated as "On the whole, I'd rather be in Philadelphia." which he might have stated at other times, and sometimes is distorted into a last dig at Philadelphia: "Better here than in Philadelphia." His actual tomb at Forest Lawn in Glendale, California simply reads "W. C. Fields 1880 - 1946".
F. Scott Fitzgerald (himself; from The Great Gatsby) -
"So we beat on, boats, against
the current, borne back
ceaselessly into the past."
Benjamin Franklin (himself) -
"The Body of
B. Franklin, Printer
Like the Cover of an old Book
Its Contents turn out
And Stript of its Lettering & Guilding
Lies here. Food for Worms
For, it will as he believed
appear once more
In a new and more elegant Edition
corrected and improved
By the Author
Robert Frost (himself) -
"I had a lover's quarrel with the world"

G
Rene Gagnon (unknown) -
"For God And His Country
He Raised Our Flag In Battle
And Showed A Measure Of His
Pride At A Place Called "Iwo Jima"
Where Courage Never Died"
Jackie Gleason (himself) -
"And away we go!"

H
Winifred Holtby (by herself) - 1898-1935
"God give me work while I may live, and life till my work is done."
Henry II (by Ralph of Diceto) -

"I was Henry the King To me Divers realms were subject, I was duke and count of many provinces. Eight feet of ground is now enough for me, whom many kingdoms failed to satisfy. Who reads these lines, let him reflect, upon the narrowness of death. And in my case behold, the image of our mortal lot. This scanty tomb doth now suffice, For whom the Earth was not enough.".
Werner Heisenberg (unknown)
"He lies here, somewhere."

This is a pun on the famous Heisenberg Uncertainty Principle, which implies that one may not know the position and momentum of a particle simultaneously.

J
Thomas Jefferson
Author of the declaration of American independence
of the statute of Virginia for religious freedom
and father of the university of Virginia
Jesse James(by his mother)
Murdered by a traitor and a coward whose name is not worthy to appear here
George Johnson (unknown) -
Here lies George Johnson
Hanged by mistake, 1882
He was right
We was wrong
But we strung him up
And now he's gone
Carl Jung (unknown) -
"Vocatus atque non vocatus
deus aderit"
Invoked or not invoked, God will be present.
Jeremiah Johnson (unknown) -
I told you I was sick.
John Jones (by Himself)
Hold my drink, you're gonna' love this.