Lindsey sneaking into George Harvey's house and stealing a notebook containing his plans to kill Susie, then managing to escape after he comes home and chases her.
Susie gets one herself at the start. When her brother swallows a twig she runs to the garage, steals the keys to the car and drives her brother to the hospital by herself, causing a bit of road rage along the way. Doubles as a Crowning Moment of Funny from the looks on her parents' faces as she drives by.
This troper, who honestly HATED Abigail in the book, could not help but feel pleasure when Buckly, who is all grown up now, says "Fuck you" to her when she returns. His older sister and her fiance don't even intervene when he says it. This troper feels that this is a triumph to all kids who have ever have a parent leave, be absent for most of their lives, and then finally return. Those two words are enough to sum up all of the hurt and anger without going into a full out rant.
Harvey's death. Just when you think he'll never be brought to justice, sweet karma intervenes, and sends him falling to a very sharp, painful and well-deserved death.
He deserved death, no doubt, so the fact that he did die is awesome, but some people were disappointed with how it happened.
Unless you believe that Susie may have had something to do with it...