And going into more meta, the fact that they were actually able to keep it a complete secret until the reveal, down to making statements that Suede didn't want to be on the site anymore, and even with his voice in the beginning of the trailer! Ron Moore would be proud.
Consider the circumstances: Suede had just returned from a two year absence; even if you overlook the fact that the entire topography of the site had changed in his absence (he asked for help in his Twitter because he couldn't find the new Premium Area) and the site's host had switched from REVVƎЯ to Blip TV (possibly costing him two years worth of ad revenue), he was no doubt still adjusting to life back at home. And on top of that, he got married two weeks before filming! The fact that he was able to participate in the anniversary at all is a moment of awesome in itself.
A lesser moment, but related to the above, is Critic figuring out Malachite sent the chain letter and is following the map to the gauntlet. Considering his characterization from the last crossover was basically an idiot, this is impressive for him.
EVERYONE in the battle in Part 6. Pretty much the CMOA of the entire site.
The Critic's opening Rousing Speech, and excellent impression of Link's "EYAH!"
Especially awesome when you remember two years ago, back to the original anniversary special, how he could barely scrap together any kind of speech at all for his team.
Obscurus Lupa shedding the useless princess persona and biting Cat, then kicking ass with a machine gun. Even Angry Joe is impressed.
Not to mention right before when Mai-Ti shows up and the reviewers are begging him not to confront Malachite... only for Ma-Ti to state that he knows exactly who he's dealing with and that he's screwed, but after all the abuse he's went through both on Captain Planet and from The Critic, he's not going to die like a pussy. Then we find out his ring is the same one Aeon used...
Ma-Ti: Oh, I know, Critic. I know. "Ma-Ti can't do anything." "Ma-Ti's totally useless." "Ma-Ti can't possibly be useful for this adventure, can he?"
Critic: Ma-Ti, seriously, not a good idea.
Ma-Ti: Lemme guess, this is the big bad sorcerer that's gunna kill us all, huh? Well I have just one thing to say to you, buddy—go. To. Hell. Go. To. Hell. You think you're sooo tough, Mr. Supercalifragilistic-sorcerer's-apprentace. Well you don't scare me one bit. HAAA!
Lupa: No, Ma-Ti, you really don't understand...
Ma-Ti: No, you don't understand. I'm tired of being kidnapped by polluting industrialists. I'm tired of getting fifth billing to WHEELER. And stupid Gi! This guy can't hurt me anymore than Ted Turner can, or the Critic, or his "friends."
Mickey: No, seriously, Ma-Ti—he will fucking kill you.
Ma-Ti: You think I don't know that? You don't think I'm totally screwed? (to Malachite) You know—you're going to totally rip me apart, aren't you.
Ma-Ti: Yeah. So I'm not going to be surviving today. But that doesn't mean I have to go out like a pansy. I'm gunna do what I always do—pull out my ring, point it at him, and say HEART!"
"EAT! MY! HEAAAAAART!"
The beautiful stained-glass artwork that appears over the end credits, displaying portraits of each of the players —and ending with opposing panels of Malachite and Ma-Ti.
Doug was apparently scared for a ridiculously long time after he thought, right there on the set, that this won't be funny, and that the whole thing was going to fail, even saying in Benzaie's VLog that he hated putting his friends through stress so much that he was thinking of canceling it. Everyone should be proud of themselves for the amount of work they put in, but he should be most of all.
The way everyone pulled together really is something. There's a clip where the group is discussing the weather problems that are slowing down production. Angry Joe speaks up and says that if they have to, Team 2 is perfectly willing to do all their shooting in the pouring rain.
The making-of special on the DVD shows that things looked so hopeless during filming that Doug, Rob, and Mike Michaud were all fully prepared to scrap the whole thing and simply film everyone hanging out in Chicago as the special. Holly told them everyone wanted to get the film done, so they tried to have a vote. Linkara stands up to say the voting is pointless, because they already know everyone would say yes. He then goes into a speech (backed up by all the other producers giving a cappella stirring music of "Glory Glory Hallelujah") that Doug is the reason that every one of them has a job on the site, and they're going to finish this thing for him no matter what. There might as well have been an American flag waving behind him. Doug thanks them profusely and leaves, newly energized to figure out the best way to finish the film. At the wrap party, he formally thanks everyone for the speech, and surprises Holly with a bouquet of roses.
Sometime after filming began (according to the group commentary), MarzGurl's original costume was lost when their hotel's housekeeping accidentally took it with the dirty laundry. So she fashioned herself a new one from scratch using whatever materials were on-hand, and filming commenced without a hitch.
Rob's description of Doug's recovery from his extreme pessimism certainly makes it seem like Doug got a big one. Apparently, with help from Rob's pep talk, Doug matured more as a director in forty-five minutes than most directors do over the course of their entire careers. Holy shit.