Well, here goes a lot of quotes (Part 1):
"It's a privilege, not a punishment."
-- Meg on having the attic room during the storm. She got the room because she was eldest (privilege) but now has to withstand the heavy storm throughout the night (punishment).
"There's nothing the matter with his mind. He just does things in his own way and in his own time."
-- Mr. Murry on Charles being a 'late bloomer'.
"Usually no matter what happens people think it's my fault, even if I have nothing to do with it at all."
-- Meg on the fight with the Henderson boy
"'Maybe if I weren't so repulsive looking -- maybe if I were pretty like you -- ' 'Mother's not a bit pretty; she's beautiful,' Charles Wallace announced, slicing liverwurst. 'Thus I bet she was awful at your age.' 'How right you are,' Mrs. Murry said. 'Just give yourself time, Meg.'"
-- The conversation between Meg, Charles and Mrs. Murry on beauty
"'I do face facts,' Meg said. 'They're lots easier to face than people, I can tell you.'"
-- Meg retorting to Mr. Jenkins when he tells her that her father isn't coming home.
"The heart has its reasons, whereof reason knows nothing."
-- Mrs. Who, on stealing the white sheets (Mrs. Who practically speaks in quotes so I won't write down all the quotes she says, just the ones I particularly like).
"You don't know how lucky you are to be loved."
-- Calvin to Meg.
"'Do you think things always have an explanation?' 'Yes. I believe that they do. But I think that with our human limitations we're not always able to understand the explanations. But you see, Meg, just because we don't understand doesn't mean that the explanation doesn't exist.'"
"'I like to understand things,' Meg said. 'We all do. But it isn't always possible.'"
-- Meg and Mrs. Murry's conversation on explanations and understandings.
"People are more than just the way they look."
-- Mrs. Murry on Charles and people.
"They can't understand plain, ordinary love when they see it."
-- Calvin on the townspeople who spread rumours about Mr. and Mrs. Murry.
"'Well, you know what, you've got dream-boat eyes," Calvin said. 'Listen, you go right on wearing your glasses. I don't think I want anybody else to see what gorgeous eyes you have.'"
--Calvin to Meg about her eyes. :)