Frodo: It's a pity Bilbo didn't kill him when he had the chance.
Gandalf: Pity? It was pity that stayed Bilbo's hand. Many that live deserve death. Some that die deserve life. Can you give it to them, Frodo? Do not be too eager to deal out death in judgment.
Frodo: I wish the ring had never come to me. I wish none of this had happened.
Gandalf: So do all who live to see such times. But that is not for them to decide. All we have to decide is what to do with the time that is given to us.

Favorite lord of the ring quote.