The Death of Volgin
Scenario: Volgin's a pretty epic boss fight, since he doesn't exactly go out with a whimper. After taking on Snake in a fistfight, chasing down Snake and EVA on the motorbike, then finally coming after them in the Shagohod, Snake finally downs him once and for all. Remember those exclamations like "by Zeus' thunderbolt?" Pretty apt here.
Sterling: Volgin's a real bastard, probably the most despicable villain in the series, and after repeated battles, it feels really good to watch him die. Anyone else agree?
AJ: I dunno if I enjoyed it, but it was certainly a nice light show when he started going all Jiffy Pop. What a way to go. But yeah, always nice when a villain goes out ironically.
Sterling: Between you and Will, I want to go home and make some popcorn.
AJ: I don't know what that means.
The Boss Reveals All
Scenario: After leading a wounded EVA to the escape point and a jet, Snake encounters his mentor, The Boss. It won't be so easy to finish her off, though. Among the many things he learns from her... oh, heck, why should we spoil the fun? The scar, however, is genuinely significant. It's ultimately her mission to fight him to the death.
Sterling: It's like a fireworks display of spoilers here. Finally, we have a degree of understanding as to why she's done what she has, and the idea behind the Cobra members makes a lot more sense. The story doesn't come full circle here, but it gets to about 330 degrees as Snake must fight his mentor to the bitter end.
Eduardo:This is probably one of my favorite moments of the series, as it does a fantastic job tying up so many loose ends left during the truly confounding MGS2. The Boss explains so much in a fairly lengthy cut-scene that it's difficult to take in everything in a single session. One of the things I like most about all of these revelations is that it's just the tip of the iceberg. The best part of this moment is that it leads up to the profound fight between the master and the student.
AJ: Oscar clip!