We discovered many a fine moment previous to that, of course. For example, I must make mention of "The Ember Island Players" episode. HAH!! It's like the condensed parody version of the whole series till now. Love. Fake-Zuko's rippling Revlon hair might've been my favorite, though Chinese-dragon Appa was cool. Also appreciated the remark, "Your Zuko costume's pretty good, but your scar's on the wrong side."
As for coolest moment, the episode with Zuko and Aang meeting the dragons was way up there. Gorgeous.
And most heart-wrenching, going back a bit, was Appa being lost for a while. It's gentle compared to the heart-wrenching moments of LOTR or Buffy, but still, so sad, as anyone who's ever had a pet can attest. However, everything turns out okay, and that's a major piece of what I love about this series. It doesn't put your emotions *too* deeply through any wringers, nor destroy any part of your soul.
Also, the kids loved it--it began affecting them at fundamental levels. The 7-year-old now happily has jasmine tea with me at breakfast. (He says, "Mmm, jasmine tea" in an Uncle Iroh voice.) And in the bath, of course, they waterbend at each other. "Look out, it's Prince Zuko!" *SPLASH*
By far the most compelling character arc is, of course, Zuko's. I have so many warm fuzzies for his relationship with Uncle Iroh alone, but his awkward bonding with the rest of the cast was a total delight too.
(Oh yeah, on the best-of list, possibly the funniest bit of dialogue all series:
Sokka: My first girlfriend turned into the moon.
Zuko: That's rough, buddy.)
...But anyway, Zuko's arc, like Spike's on Buffy & Angel, or even Snape's in Harry Potter (kind of), is interesting because it's the most dramatic change; the most redemptive. But none of those guys are the technical heroes of the stories. Aang, Buffy, and Harry Potter all start out as pretty good people, and despite some dark moments, they never go *too* dark, and therefore their arc is only from "younger and more innocent to older and braver," without the dramatic change that the aforementioned former enemies go through.
So this makes me wonder: can a hero ever be quite as interesting as those secondary characters who go from villain to ally over the course of the epic? Just throwing that out there as something to think about.
I've also caught up now to all available episodes of Downton Abbey and Sherlock, so we can talk spoilers for those if you want. Carson, more tea, please.