More than one, but here's a few I like...
"The richest man is not he who has the most, but he who needs the least."
-???
"Watch your thoughts; they become words.
Watch your words; they become actions.
Watch your actions; they become habits.
Watch your habits; they become character.
Watch your character; it becomes your destiny."
—Lao-Tze
"I haven't committed a crime. All I did was fail to comply with the law."
-New york City Mayor David Dinkins
"In America, anybody can be president. That's one of the risks you take."
-Adlai Stevenson
"I find that the harder I work, the more luck I seem to have."
-Thomas Jefferson
"Forgive your enemies, but never forget their names."
-John F. Kennedy
"Whatever is begun in anger ends in shame."
-Benjamin Franklin