Sonic 3 and Knuckles/Awesome


 * The fight against Knuckles at Hidden Palace Zone. The boss fight is really easy and nothing special, but what makes it so awesome is that you finally get to have your revenge on Knuckles for every last cheap shot, trick, and trap that he's been pulling on you since your first encounter with him at the beginning of the game.
 * Act 2 of the Marble Garden Zone has Eggman destroying the stage itself around Sonic, dooming him to certain death. Tails, however, swoops in to carry his idol and chase Eggman down for a battle in the skies. Tails has very little stamina in the air in normal gameplay, and less so while carrying Sonic, but he hangs on through the whole boss fight and even manages to catch Sonic if he ever should fall, and then for good measure keeps going long enough for the sun to set in the background... and lands in the Scrappy Level. Maybe that cancels out the awesome?
 * Really, the fact that Eggman destroyed the entire Goddamn level just to kill Sonic is, in itself, a CMOA for Eggman. And for Sonic too.
 * The entirety of Sonic 3 & Knuckles is a crowning moment for Eggman, simply due to the sheer amount of effort he puts into it from start to finish. In the first level, he starts a forest fire with Sonic in the middle, and then as soon as the hero escapes, cue an airship bombardment. And as awesome as Doomsday Zone was, the preceding boss fight featured Eggman in a robot version of himself so titanic that its head almost filled the entire screen -- and so did its laser beam, incidentally.
 * He also managed to create a machine strong enough to knock the rings out of Super Sonic if it got a hold of him.
 * Doomsday Zone, where you fly through space as Super Sonic chasing down the ship, avoiding asteroids...
 * Temporarily defying Good Is Dumb, Knuckles gets his personal Crowning Moment of Awesome as he completes his Heel Face Turn at the end of Hidden Palace Zone, coolly smashing the wall and leading Sonic and Tails towards Eggman. Depending on who you're playing as, he either collapses from pain and exhaustion or battles Super Metal Sonic for the Master Emerald.
 * Another one of Knuckles's best moments: when he punched the Chaos Emeralds right out of Super Sonic. The invincible Super Sonic Brought Down to Normal with just one punch.