Doubles as in-universe tearjerker: Sarah harshly Complaining About Rescues They Don't Like when she reunites with John, who was expecting some warmth and affection, but is instead devastated by her callous response.
As Sarah Connor was about to murder Dyson in cold-blood in front of his family, she realizes that she has become exactly like what she hates the most, and collapses weeping in guilt.
The "burning playground" opening, juxtaposed to Brad Fidel's gentle and heartfelt rendition of the "Terminator Theme" strikes just the right emotional nerves, reminding us of how important it is to save this world for the next generation.
Hell, this entire sequence is a Tear Jerker. It's VERY heartrending to see John pleading the T-800 not to go. Even after you consider that it was the closest he ever got to have a father figure. Doubles as a Heartwarming Moment, when watched back-to-back with Sarah's final speech in the movie.
The Final First Hug between the T-800 and John is pretty heartbreaking too.
The T-800 and Sarah are both being The Stoic, as they know that this has to happen in order to prevent the creation of Skynet. John, however, simply descends into Inelegant Blubbering that leads to a truly heartbreaking Heroic BSOD: