"I'm on a roller coaster that's only going up." 

"As he read, I fell in love the way you fall asleep: slowly, and then all at once."

"Oh, I wouldn't mind, Hazel Grace. It would be a privilege to have my heart broken by you." 

"It's a metaphor, see: You put the killing thing right between your teeth, but you don't give it the power to do its killing."

"Maybe 'okay' will be our 'always."

"I'm in love with you, and I know that love is just a shout into the void, and that oblivion is inevitable, and that we're all doomed and that there will come a day when all our labor has been returned to dust, and I know the sun will swallow the only earth we'll ever have, and I am in love with you."

Guess who??