Doubling as a Crowning Moment of Funny is the scene just before the Bahamut Fury fight. Genesis summons Bahamut Fury, Zack gets ready to fight and... his cellphone rings, Aerith is calling him. Zack nonchalantly tells her he'll call her back because "I've got some company." as Bahamut Fury descends in front of him roaring.
Her response: "Don't keep them waiting."
How about Bahamut Fury's special attack? The other summons get their own impressive animations, but this one sends the dragon into outer space! Then it turns to face the moon, and shoots out it's spikes to form an energy ring in front of it. Then Bahamut reflects a FRIGGEN LAZER off the moon, and fries half a continent. By the time you realize what's going on, your're probably crapping yourself.
The beginning of the game where Zack calmly whips out his cellphone and has a conversation with Angeal while getting fired at by enemy troops. Later you find out it was a holographic simulation, but at the time it is awesome.
The beginning scene that leads up to this is awesome too. Zac jumps out of a helicopter, runs along a moving train, deflects multiple bullets, then jumps over a stream of bullets and a squad of soldiers and detatches the front train car from the others. Too bad it wasn't real.
In Sephiroth's flasback, the fight sequence between Genesis, himself, and Angeal.
The way the Nibelheim incident is told in Crisis Core. Mostly due to the extremely badass showdown Zack and Sephiroth had. In the original game, we just saw Zack being thrown out of the reactor core. In Crisis Core, it turned out the two had an epic sword fight. It could be considered to be the greatest boss battle in the game, if just for the fact that, much like Kingdom Hearts, the player goes one-on-one with the goddamn Sephiroth.
One of Zack's Moments of Awesome was charging at the entire damn Shinra Army, knowing he's going to die, then proceeding to defeat most of it and despite laying in a pool of his own blood and being full of bullet holes, he still manages to say good bye to Cloud.
This is actually a good argument for this being a Moment of Awesome for Square Enix's storytelling abilities. Put it this way: the first time watching the ending, when I saw Zack say the SOLDIER creed for the last time and charge at the Shinra army, I thought he would do so in a cutscene, or maybe the game would just cut to black and end right there. "ACTIVATING COMBAT MODE." "Wait, what?!!" Cue an incredible Tear Jerker as you proceed to play through Zack's last stand, set to heartbreaking music, and finally revealing the reason behind the silly luck-based DMW system: allowing the game to flash Zack's life before your eyes right on your PSP screen. It doesn't matter how many soldiers you kill, they'll overwhelm you eventually, and just as the final bullet hits Zack in the rain, the DMW flashes Aerith before his eyes before it crashes for good. It's quite possibly the greatest Gameplay and Story Segregation aversion in the history of the videogame industry.