Some of my favorites are:
"Man's fate is like that of the animals; the same fate awaits them both: As one dies, so dies the other. All have the same breath; man has no advantage over the animal. Everything is meaningless. All go to the same place; all come from dust, and to dust all return. 21 Who knows if the spirit of man rises upward and if the spirit of the animal goes down into the earth? 22 So I saw that there is nothing better for a man than to enjoy his work, because that is his lot. For who can bring him to see what will happen after him?" (Ecclesiastes 3:18-22)
"I have seen something else under the sun: The race is not to the swift or the battle to the strong, nor does food come to the wise or wealth to the brilliant or favor to the learned; but time and chance happen to them all." (Ecclesiastes 9:11)
"Whatever is has already been, and what will be has been before" (Ecclesiastes 3:15)
What are yours?
Joseph F. Alward
"Skeptical Views of Christianity and the Bible"