Navidson's ending (which ends in marriage, the survivors returning to normal, and the house sealed off), and the very beginning before they discover the house.
And what about Karen overcoming her fear of the dark and rescuing Navidson?
Even if it makes it worse the whole Pelafina/Johnny mother-son relationship had its moments too. Specially when Johnny opens the locket. And the Story of the Mother is heartwarming in a tragic, melancholic way.
After the horrifying events of Expedition #4, Will's twin brother Tom reverts to alcoholism, and at one point Will finds him lying on the floor drunk. He picks him up and puts his arm around him, and Tom says "At least when you're drunk, you've always got the floor for your best friend. Know why?" Will completes the saying with "It's always there for you," and Tom returns "That's right, just like you." Aw. In retrospect, this probably should have made it clear that Tom was going to die less then ten pages later—as it turned out, he couldn't count on the floor. Also, the little vignette about the locket and what turns out to be in it.
Bizarre as it is, and despite only being given second-hand, Navidson's dream about the giant snail. The account goes into quite a bit of detail about how the tone of the dream is extremely peaceful and how its imagery (like the rising spiral of the snail's shell) inverts the traumatic memories of the house.