These glorious insults are from an era before the English language got boiled down to 4-letter words;

A member of Parliament to Disraeli: "Sir, you will either die on the gallows or of some unspeakable disease."
"That depends, Sir," said Disraeli, "whether I embrace your policies or your mistress."

"He had delusions of adequacy." - Walter Kerr

"He has all the virtues I dislike and none of the vices I admire." - Winston Churchill

Lady to Winston Churchill, If I were your wife, I would give you poison. To which Churchill responded, madam, if I were your husband, I would take it!

"I have never killed a man, but I have read many obituaries with great pleasure."  Clarence Darrow

"He has never been known to use a word that might send a reader to the dictionary." - William Faulkner (about Ernest Hemingway).

"Thank you for sending me a copy of your book; I'll waste no time reading it." - Moses Hadas

"I didn't attend the funeral, but I sent a nice letter saying I approved of it." - Mark Twain

"He has no enemies, but is intensely disliked by his friends.." - Oscar Wilde

"I am enclosing two tickets to the first night of my new play; bring a friend.... if you have one." - George Bernard Shaw to Winston Churchill

"Cannot possibly attend first night, will attend second.... if there is one." -  Winston Churchill, in response.

"I feel so miserable without you; it's almost like having you here." - Stephen Bishop

"He is a self-made man and worships his creator." - John Bright

"I've just learned about his illness. Let's hope it's nothing trivial." - Irvin S. Cobb

"He is not only dull himself; he is the cause of dullness in others." - Samuel Johnson

"He is simply a shiver looking for a spine to run up." - Paul Keating

"In order to avoid being called a flirt, she always yielded easily." - Charles, Count Talleyrand

"He loves nature in spite of what it did to him." - Forrest Tucker

"Why do you sit there looking like an envelope without any address on it?" - Mark Twain

"His mother should have thrown him away and kept the stork." - Mae West

"Some cause happiness wherever they go; others, whenever they go..." - Oscar Wilde

"He uses statistics as a drunken man uses lamp-posts... for support rather than illumination." - Andrew Lang (1844-1912)

"He has Van Gogh's ear for music." - Billy Wilder

"I've had a perfectly wonderful evening.  But this wasn't it." - Groucho Marx