This cutscene from Sonic Adventure 2. It perfectly displays the character relationship between Sonic and Shadow and sets a mood that if Shadow isn't stopped here, Eggman will take over the world (Well when played from the Hero's side anyways...) The music just makes it all the more epic.
Actually, at that point in the Hero Story, Eggman has already been defeated by Tails.
Yes, his mech was destroyed by Tails, but it's clear that in both stories he was able to signal Shadow to go after the trespasser headed to the cannon.
And in another case of playing possum, Eggman actually made off with the final Chaos Emerald after the fight.
About halfway through Sonic Adventure 2, after organising Shadow and Rouge to raid and detonate an entire island, and with six of the seven Chaos Emeralds in his possession, Dr. Eggman declares himself ruler of the Eggman Empire, announces to the entire world that they will surrender or die, and, just to prove he isn't fucking around, powers up the Eclipse Cannon and blows up half of the moon.
Personally, I vote for when, attempting to trick him with a fake Emerald, Robotnik completely pwned Sonic and the gang at their own game and shot our hero into space to certain death. The most shocking part? If it wasn't for a last minute Deus Ex Chaos Control, Sonic. Would. Have. Been. Dead. That is the true genius of a man with a 300 IQ.
You can add to this the moment when Eggman tricks Tails into revealing the emerald was a fake to begin with. After seeing a guy who we're constantly told has an IQ of freaking 300 do so many stupid things, it's nice to see him actually express his intelligence for once.
Tails: So... how did you know it wasn't the real one?
Even better, playing both parts of the game reveals that Eggman had already deduced Tails had a fake emerald long before that encounter, so not only did he pwn them at their own game and rub their faces into it, but he screwed with their minds by lying about how he knew, making them out to be even bigger idiots than before. Awesome.
Not quite, since he couldn't know which one of the two was the real one, so he trapped Sonic without knowing and then Tails told him.
No, he obviously knew. People aren't just handed 300 I.Q.'s you know.
In one of the cutscenes in the Dark Story, Eggman detects two Chaos Emeralds, knowing that Sonic and the others would try to trick him by giving him the fake one. In other words, he knew that it was a fake as soon as Sonic and his group arrived on the Ark.
Also, Sonic — who had never before used Chaos Control and only ever seen it being performed once — manages to pull off Chaos Control using a FAKE Emerald. Even Shadow was impressed.
The opening level of Sonic Adventure 2 is pretty awesome. It's not everyday you see someone freefall out of a helicopter and then board down the side of San Francisco with a part of the wing.
While performing sick air tricks and shit.
Heck, what about Eggman's first level? The Dark story opens with him charging Prison Island, guns blazing and his theme triumphantly flaring.
Sonic: You can't get away this time! There's only one. Real. SONIC!
Shadow had a very overlooked moment of awesome. He fell to Earth, from SPACE, and SURVIVED. Come on, ultimate lifeform or not, that's gotta count for something.
One of my favourite Shadow moments, and moments in general, is in Sonic Adventure 2, during the Last story. While everyone (including Eggman) is racing around trying to stop the Space Colony ARK from falling to Earth, Shadow just stares down at Earth, claiming that he doesn't need to help because it's useless anyway. After Amy gives him a speech about how, even though Humans Are Bastards, they can be good too, Shadow finally remembers Maria's true final words: "Give them a chance to be happy!" and quickly runs off to the cannon's core. Meanwhile, Sonic and Knuckles are preparing to do battle with The Biolizard, when suddenly they hear; "Leave this one to me." Shadow walks towards his prototype, calm determination etched into his face, while Sonic and Knuckles stare at him bewildered. Shadow whirls around, declares "I'll take care of this, while you run to get the Chaos Emeralds!", trashes The Biolizard in an epic one-on-one battle, and finishes with "GET OUT, YOU UGLY PROTOTYPE!"
Try running around Chao World with Sonic. Now do it with Eggman (who goes without his Walker). Notice something? THEY RUN AT THE EXACT! SAME! SPEED! Just the fact that they remembered that even for something as small as Chao World says something! It may be a small detail, but This Troper was in awe when he ran around Chao World with Eggman for the first time and saw how fast he was running.
This troper always assumed it was a reference to the final levels of the original game and its sequel, where it was shown that Robotnik could ironically outrun Sonic when fleeing from a failing mech.
Amy's entire involvmeent in this game is a crowning moment for her developmentally. In Sonic Adventure, Amy was a frightened hostage who spent most of her time running away from someone or something until she finally decided to stand on her own two feet and fight her own battles. She then decided to become a stronger person and teach Sonic to respect her and this game perfectly shows just that. Right out the gate, she's the FIRST one to jump into action when Sonic is arrested, beating even TAILS to Prison Island. With Tails' assistance, she then sneaks into the prison, steals a security card and lets Sonic free. While she does fall into the background a bit until the last story once they get off Prison Island, she's still a fugitive on the run, a contributing member of Sonic's team and, if her appearance in 2P mode is to be taken as truth, her athletic skills have developed from slightly above average with her hammer to full on Badass Normal, with her able to play by Sonic's rules and decently keep pace with him. While she goes overboard in later games and becomes a hotheaded psycho, this game showed perfectly what a little bit of self confidence and determination can do for a girl who's only notable contributions prior to then were getting herself kidnapped.
Tails gets one in the game as well, for showing off that his engineering genius rivals, if not surpasses Eggman's. How does Tails do this? The fake Chaos Emerald of course. Think about it, the Chaos Emeralds are ancient and powerful beyond belief, and Tails MADE ONE. Yes it was fake, yes it was designed to destroy the Eclipse Cannon if put into the core, but in the end it implies that Tails originally made a perfect copy of the emerald and only later modified it. Eggman looked and saw two Chaos Emeralds, so he deduced one was a fake, but it would imply that like the original emerald the fake gives off tremendous energy. Long story short Tails can MAKE Chaos Emeralds, Eggman can't boast that.
"Can you hear me, Sonic, Shadow? Everyone here is rooting for you! Good luck, and give him trouble!"