Ares shooting a gatling gun while drinking a beer with other hand, or surfing on a bomb in his mini.
Spider-Woman's fight with Madame Masque in the fog.
Thor's fight with Bor, especially when he casually tosses the Dark Avengers out of the fray.
The Young Avengers beat the Dark Avengers so badly that Osborn tells them "This doesn't count. This officially isn't part of Avengers History".
Mr. X blocking multiple bullets with his swords.
Phobos finally living up to his name and practically making Osborn fill his pants. Bonus points for Ares' proud poppa reaction to it.
Two She-Hulks fighting in the air.
Cage tricking Osborn and beating his people with Wrecker's crowbar.
The truck trick Deadpool pulls when a rocket launcher's fired at him. Even Bullseye has to admit it's cool.
Cyclops handing Norman Osborn his ass in Utopia.
Iron Man returning to action in an inferior suit to the stolen "Iron Patriot" armor Osborn was using, and disabling it within seconds of his arrival. Spider-Man even lampshaded the moment while watching. "And suddenly it's all worthwhile."
Quicksilver overwhelming Mr. X - he took on a perfect killer, who can anticipate his opponents moves, armed with a weapon equal or stronger than Mjolnir, and handed his ass over to him with a metal pipe, while (relatively) slowly monologuing how X's powers are completely useless against the fastest man on Earth.
Deadpool owning the Thunderbolts (with Taskmaster's help admittedly) and kicking Bullseye around (which ends with the aforementioned car trick).
Daken's luring the X-Men into Central Park and outwitting them, taking them down and stealing the Muramasa Blade. Sets him up as a Magnificent Bastard.
Mockingbird, not long back from being held prisoner by the Skrulls, manages to hold her own against an entire group of villains when the rest of the New Avengers are put out of the game. When she's eventually knocked down (more villains arrive, ones around about Thor's level), she disappears. Then she returns, lands the quinjet ON TOP OF OSBORN, and yells at the other New Avengers to assemble — as in, get their asses up and go.
Sentry was always an extremely powerful being, but when the Dark Avengers, lead by Norman Osborn, encountered a town under Molecule Man's control, it became clear just how powerful he really was. After being ripped apart at the molecular level and scattered to the winds by Molecule Man, Sentry suddenly reforms himself and proceeds to obliterate Molecule Man, but not before forcing him to fix all the damage he'd caused. That leads to this exchange:
Sentry: "I learned something about myself today." Norman: "What's that, Robert?" Sentry: "I can control the molecules of my world. That's how I do what I do. I never knew that. How could I? No one could. Not Reed Richards. Not Tony Stark. All they knew was I was different." Norman (scared): "We're all different, Bob." Sentry: "We're all different. Now I can see how and why. Now I can control it."