For snarky and sarcastic quotes, despair.com has some cool new t-shirts:

"Toyota - once you drive one, you'll never stop."

"If you don't like my opinion of you, you could always improve."

"The more of my behavior you accept, the less you will have to forgive."

"Don't ever change. I always want to be better than you."

Bears, beets, Battlestar Galactica.