It needs the first sentence for context, but the main one just destroys me.
What was it that Granny Weatherwax had said once? ‘Evil begins when you begin to treat people as things.’
And right now it would happen if you thought there was a thing called a father, and a thing called a mother, and a thing called a daughter, and a thing called a cottage, and told yourself that if you put them all together you had a thing called a happy family.
Obviously, it (greatest sentence) will depend on the context: where it’s coming from, where it’s going and what it’s supposed to do. Insofar as standalone sentences that provoke vivid mental images, I’ve always liked this one:
“The motorcycle engine died with a prolonged series of soft smoky gasps—like a dwarf choking on a burning rag.” (Tom Robbins, “Another Roadside Attraction”)
Dave Barry has some great ones:
“A person who is nice to you, but rude to the waiter, is not a nice person”
And this one, which I’ve only just seen:
“You can only be young once. But you can always be immature.”
“I thought I was God.” --a cocaine user, from Time, 1983.
Good thing he wasn’t an atheist.
That’s absolutely the best sentence ever. I love it. Kid has got a great career ahead of him/her.