Everything hits the perfect notes it needs to hit, the fight, the second half, the music, the moment.
Composers have even been shown this boss fight and have commented on how amazing the music sounds and how wonderfully it fits the game.
Edit... Runner up for me:
Also a near perfect moment that shows you exactly how powerful the main character is to let you know that you can parry nearly everything, no matter the size of the opponent, while the adrenaline rush of the lyrics kick in with the electric guitar.