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 has never been known to use a word that might send a reader to the dictionary.' - William Faulkner (about Ernest Hemingway).
'Poor Faulkner. Does he really think big emotions come from big words?' - Ernest Hemingway (about William Faulkner)
'Thank you for sending me a copy of your book; I'll waste no time reading it.' - Moses Hadas
'There's nothing wrong with you that reincarnation won't cure.' Jack E. Leonard
'They never open their mouths without subtracting from the sum of human knowledge.' - Thomas Brackett Reed
'In order to avoid being called a flirt, she always yielded easily.' - Charles, Count Talleyrand
One of mine: The great and powerful (insert name) speaks! Pay no attention to the man behind the curtain.
(not entirely original, but gets great laughs from the people who know the person I say it about.)