* This exchange:
-->'''Donnie:''' How does it feel to have a wacko for a son?\\
'''Rose:''' [[spoiler:''It feels wonderful.'']]
* The ending is this completely. The worst part is when [[spoiler:they show Frank at the end of the "Mad World" montage just sitting there. Implying that, seeing as the other people in said montage remembered Donnie in some way, [[CrowningMomentOfHeartwarming he's going to skip Halloween to remember someone he never even knew.]] To top it off, he tried to warn that person and failed]]. Now imagine how you would feel in his shoes.
** Donnie lets himself [[spoiler:get crushed to death by the airplane, because if he doesn't, the world will end on Halloween night]] Then, the song "Mad World" starts playing at the credits, and you [[http://www.youtube.com/watch?v=DR91Rj1ZN1M really start to lose it]].
* The part that really got to me (it may have only been in the director's cut) was when Donnie gets into a debate in his English class over ''Watership Down'', asking why the reader should care if the stupid rabbits live or die, and he sounds pretty desperate. [[spoiler: He is so clearly trying ''not'' to be the Messiah, to convince himself he shouldn't have to die for these foolish, ungrateful people.]]
* This line from Frank.
--> I'm so sorry Donnie.
** This makes sense, as [[spoiler: he is one of the manipulated dead (long story), and is apologising in advance for killing Gretchen.]]