Hazel: The only person I really wanted to talk to about Augustus Waters's death was Augustus Waters.
"The beautiful couple is beautiful".
"Gus, my love, I cannot tell you how thankful I am for our little infinity." The entire scene at Augustus's prefuneral, really.
Augustus' breakdown in the gas station parking lot.
Hazel's mom. "I will always be your mom, Hazel."
The above counts more for happy tears. The line that leads up to it, much earlier, "I won't be a mother anymore." is one of the most powerful lines in the book.
Even more emotionally jarring when you consider how well Augustus knew Hazel. He was most probably expecting and hoping for that exact response to invoke the "spiritual marriage".
The reason Peter van Houten is such a drunken ass. His daughter died of leukemia, which is what inspired him to write An Imperial Affliction. Hazel reminds him much of his daughter, which is probably why he treats her like shit; it's too painful for him.
"It would be a privilege to have my heart broken by you, Hazel Grace." Especially when you realize at that point, he knows he's dying. He's saying it would be a privilege to live that long.
The first trailer for The Film of the Book. The shot of Hazel's mom running into Hazel's room while Hazel lays there screaming in pain on her bed really hits, hard.
Peter van Houten, after exiting Hazel's car, looks at her for a moment, glances at the flask of whisky in his hand, and just for a moment, you think he'll leave it behind. And then he doesn’t.