"A lesson without pain is meaningless, for you cannot gain something without sacrificing something else in return, but once you have overcome it and made it your own...you will gain an irreplaceable, fullmetal heart." - Fullmetal Alchemist Brotherhood, Episode 64 (Epilogue).
"Possibly humans can exist without actually having to fight. But, many of us have chosen to fight. For what reason? To protect something? Protect what? Ourselves? The future? If we kill people to protect ourselves and this future then what sort of future is it and what will we have become? There is no future for those who have died. And what of those who did the killing? Is happiness to be found in a future that is grasped with blood stained hands? Is that the truth?" - Lacus Clyne - Mobie Suit Gundam SEED Episode 49: The Final Light
"Love is like a mirror that reflects your bad side. Especially when it's unrequited, you get envious, jealous, prejudiced and resentful. You have to face all sorts of emotions" - Margery Daw - Shakugan no Shana
And although this is from the manga and not the anime, it still counts because it's so awesome:
"Because I've been dead for so long, I don't really get what's going on. But, why does everyone feel that they should have big breasts? Is it to prepare for a famine where you need to store nutrition or something?" - Oshizu - To Love Ru, Chapter 156