#1. First favorite soundtrack moment of epiphany. Although Philip Glass composed it for a previous film Powaqqatsi, its usage in The Truman Show wordlessly encompasses the protagonist's first enlightenment to his predicament, and the bizarre meaning of his own life. Perfect, and almost biblical in its implications of uncontrollable forces vs. self-determination, like Patrick McGoohan's original The Prisoner. (Plus I'm a sucker French horns, since they're the same timbre as the male voice.)
Watch the sequence in the film, not this snippet, and it will all make sense to you as well as the character. The film becomes more relevant by the hour as scripted drama falls by the wayside and reality shows become synonymous with regular broadcasting. Pure, and far-sighted brilliance from director Peter Weir and writer Andrew Niccol.
#2. From Magnolia, the entire cast of characters' realization that they must change change their respective, troubled lives. I interpret Aimee Mann's last verse as giving up resistance to wising up, and really felt for Melora Walters' lost girl and the little quiz show child.
#3. Now for some derring do. The below sequence includes the longish set up for the sudden 'this is what I must do at this point in my life' song choice. And which other one could launch the instantaneous bravado to overpower single-handedly an entire yacht swarming with modern, armed, hostile pirates as much as this song? From The Life Aquatic with Steve Zissou starring the redoubtable Bill Murray...