Jane Austen - So we can hear her ever so subtle thoughts in all of the Austen fan fic, Pride & Predjudice and Zombies, etc.
Shel Silverstein - lines of his poetry are just built for twitter. ”If you are a pretender come sit by my fire.”
Andy Kaufman - just imagine the twitpic account.
The Founding Fathers - so they can set those dumb ass Tea Baggers straight about what they “really” intended.
Martha from Albee’s “Who’s Afraid of Virginia Woolf?” - The gin soaked rants would be brilliantly quotable.