This thread is wonderful. :)
I have many favourites, I'll try to contain myself a little but it's impossible for me to pick just the one -
"So we beat on, boats against the current, borne back ceaselessly into the past." - The Great Gatsby, F. Scott Fitzgerald
"I took a deep breath and listened to the old brag of my heart. I am, I am, I am." - The Bell Jar, Sylvia Plath
"Today I must be very careful, today I have left my armour at home." - Good Morning Midnight, Jean Rhys
"But wherever they go, and whatever happens to them on the way, in that enchanted place on the top of the Forest, a little boy and his Bear will always be playing." - The House at Pooh Corner, A. A. Milne (that one always gets me)
And one that will always hold a place in my heart:
"The scar had not pained Harry for nineteen years. All was well." - Harry Potter and the Deathly Hallows, J.K. Rowling