First, by the amazing Elie Wiesel:
"The opposite of love isn't hate, it's indifference".
A friend of mine reminded me of this one tonight. Hate is such a passionate emotion, but indifference -- that's cold and final. And makes much more sense.
"When you play in the mud with a pig - the pig has fun and you get muddy."
Not sure who said that originally, but funny, and TRUE! Mudslinging doesn't work when you're playing with a pig.