Ser Robar Royce, after a little convincing from Catelyn, held off several of the South's best knights to allow two women he knew were innocent to escape Renly's camp.
Yoren's confrontation with a gold cloak asking for one of the boys in his charge made him pretty awesome:
Gold Cloak: I'll have the boy.
Yoren: You'll have no one. There's laws on such things.
Gold Cloak: *draws a shortsword* Here's your law.
Yoren: That's no law, only a sword. Happens I got one too.
And then the others all get their weapons - hammers, knives, walking sticks - and prepare to fight the Gold Cloaks. Even Hot Pie grabs a rock.
Another awesome moment for Arya is how she ropes in Jaqen H'ghar. She has an assassin on a leash who will give her three deaths, and she's already got two. When he won't go along with her plan, she asks him to kill himself.
"The Wolf in the Night:" Robb Stark smashes a Lannister host at Oxcross and proceeds to drive deeper into the Westerlands, cementing his reputation as a Young Conqueror.
Two Brave Companions climbed up the ramparts and ripped down the banners of the Lannister lion and Ser Amory Lorch's manticore, replacing them with the direwolf of Stark. And that evening, a page named Nan poured wine for Lord Roose Bolton and Vargo Hoat as they sat on the gallery, watching the Brave Companions parade Ser Amory Lorch naked through the middle ward. Ser Amory was sobbing and pleading and clinging to the legs of his jeering captors, until Shagwell pulled him loose and kicked him down into the bear pit. The bear is all black, Arya thought. Like Yoren. She filled Roose Boltons cup, and did not spill a drop.
It also serves as a fantastic Kick the Son of a Bitch moment for the Brave Companions. You may end up hating them later, but there's no denying Lorch had it coming.
Tyrion nearly surpasses Littlefinger himself in a single damn chapter. He suspects that one of three councilors (Pycelle, Littlefinger, and Varys) is a spy for Cersei. To flush out the rat, he gives each of them a different story about the plans he has for two of Cersei's children. So when a furious Cersei comes to him ranting and raving about the plans he had "entrusted" to Pycelle, he instantly knows it was the Grand Maester spying for her. Game, set, match.
The deformed dwarf Tyrion Lannister rallying troops for the defense of King's Landing:
"They say I'm half a man. What does that make the lot of you?"
When Tyrion is planning the defense of King's Landing, and orders the troops to practice with the flamethrowers, starting with green paint and working their way up to lamp oil, by taking the advice of the expert. Don't see that nearly often enough in high adventure.
Tyrion coming to the defense of Sansa who was getting utterly humiliated by her husband-to-be definitely counts as well.
When Tyrion turns table on a knight who just unhorsed him by head-stabbing his horse is also a Moment of Awesome.
While we are at Wildlings, Osha's actions and loyalty to the Stark family during a Clash of Kings are quite awesome in their own way. Especially killing two armed Ironborn guards with a kitchen knife, if Theon's observations are to believed.
Ser Cortnay Penrose, castellan of the castle Storm's End, facing Stannis, who's trying to convince to surrender by telling him there will be no mercy if he has to take the castle by force -
Penrose: "Very well, Ser. Bring on your storm. And remember, if you will, the NAME of this castle."
And earlier — all of Stannis' men are scared shitless of Melisandre; Penrose openly tells her that the Others can wipe their ass on the Lord of Light's flag.
Asha, sister to Theon Greyjoy who, after his return, completely and utterly humiliates him. She pretends to be a shipwright's wife and mock seduces him to learn his nature. When he finds out, he's gobsmacked, remembering her as a plain child, not a beautiful, intelligent, tough woman. Then, when he confronts her about her deception, she claims she does have a husband and child... and reveals an axe and a small dagger.
Seeing Podrick Payne reveal that he is in fact a Crouching Moron, Hidden Badass by killing a member of the Kingsguard and then getting Tyrion to safety.
Podrick gets better, he's still loyal after all this time to Tyrion, long after Tyrion left him behind.
And later in the series, he distracts Shagwell by throwing rocks at him, so that Brienne only has to face one of the Bloody Mummers at a time.
"I told you I could fight!"
Hodor smashing out of the crypt at the end of the book. Really makes you glad he's a Gentle Giant.
As shitty a person as he is, Balon Greyjoy has a badass line during his introductory chapter.
"I am the Greyjoy, Lord Reaper of Pyke, King of Salt and Rock, Son of the Sea Wind, and no man gives me a crown. I pay the iron price. I will take my crown, as Urron Redhand did five thousand years ago.
Directly after which, Theon fires back with his first display of guts."Call yourself King of the Iron islands, no one will care... until the wars are over, and the victor looks about and spies the old fool perched off his shore with an iron crown on his head. Which ends up being a pretty effective summary of the Iron Islands storyline for the next several books to follow
Theon Greyjoy in general does not receive nearly enough credit for his achievements as a character. Taking the great castle of Winterfell with only a handful of men is not something to balk at. Whether it can be considered a morally reprehensible action or not, it took guts and no small amount of tactical intellect.
Sansa, on receiving a mysterious message summoning her to the Godswood, which could easily be a trap meant to test her loyalty to the Lannisters, decides to investigate, and arms herself with a knife to sneak through the spy-filled Red Keep at night to meet Ser Dontos for the first time.
After the riot breaks out in Fleabottom when Joffrey orders the Hound to kill all the peasants, Tyrion assumes that the Hound was overrun and killed by the horde. Just minutes later the Hound returns to the Red Keep with Sansa over his shoulder. Not only was he able to fight his way through a riot where everyone was trying to kill him, he was able to save Sansa from being raped and murdered without getting injured.
In Sansa's first POV chapter, when Joffrey demands that Ser Dontos should be executed for showing up to the tourney drunk, Sansa immediately speaks out in protest in spite of how terrified she is of Joffrey and, with some help from Sandor Clegane, actually succeeds in convincing him to spare Dontos.
The Bridge of Ships. Stannis Baratheon is often thought to be too grim & rigid to inspire true loyalty among his men. Even Stannis himself believes this. Despite this, at the height of the Battle of the Blackwater, hundreds of Stannis's bravest knights & men-at-arms charge willingly across the river Blackwater over a impromptu bridge of burning ships, surrounded by a maelstorm of supernatural Greek Fire into heavy armed defenders. Even Tyrion, commanding the enemy forces is impressed. Ladies & gentleman, if that is not loyalty I don't know what it is.