Shasta/Cor Jumping off Bree's back (who, despite being a war horse who's been through a thousand battles, is too scared out of his mind to do anything but run) to face down a freakin' lion who's actually Aslan, (the god of all creation in Narnia!) chasing Aravis and Hwin. Don't get me wrong, it's a stupid idea which even the narrator calls "idiotic" - but it proves Shasta's devotion to his friends, as well as having balls of dwarf-forged steel. Note that he's about ten years old and completely unarmed, so that the best thing he can do is yell at it. Pure Awesome.
Leads to a Crowning Moment of Heartwarming a few pages later when, after Shasta has already left to find King Lune, each of his friends compliment his actions and Aravis, who admits she has looked down on Shasta the entire time up until that point, says that he had been "marvelous".
Aslan gives Rabadash a chance to escape the Humiliation Conga he's setting himself up for: "Have a care, Rabadash. The doom is nearer now. It is at the door, it has lifted the latch..." (Performed to marvelous effect by Anthony Quayle in one of the audiobook readings.)
Prior to that, Rabadash jumped from the top of the wall of a castle... but he gets his chainmail shirt caught on a hook, and hangs there, stuck. Later, while a captive, Rabadash again threatens the heroes:
Rabadash: "The bolt of Tash falls from above!"
Corin: "Does it ever get caught on a hook halfway down?"
Lune(Corin's father): "Shame, Corin. Never taunt a man save when he is stronger than you; then, as you please."
Shasta running non-stop, after having been through almost a whole book's worth of shit — most recently a potential suicide mission through a desert — to warn King Lune about the impending invasion.
Corin Thunder-Fist versus the Lapsed Bear of Stormness, a talking bear who went feral and lost the ability to speak. Note that, as the epithet implies, Corin is a boxer. Too bad we don't actually get to see it.
Likewise Peter, who is absent the whole book because he's off beating the hell out of a bunch of giants.
Edmund gets a great one as Rabadash is hanging on the wall. Rabadash demands to be let down and given a fair shot at killing Edmund. Edmund's response is basically, "'Kay." (Sadly, King Lune intervenes, though his answer is fairly awesome in its own right.)
"By your Majesty's good leave," said King Lune to Edmund. "Not so." Then turning to Rabadash he said, "Your royal Highness, if you had given that challenge a week ago, I'll answer for it there was no one in King Edmund's dominion, from the High King down to the smallest Talking Mouse, who would have refused it. But by attacking our castle of Anvard in time of peace without defiance sent, you have proved yourself no knight, but a traitor, and one rather to be whipped by the hangman than to be suffered to cross swords with any person of honour. Take him down, bind him, and carry him within till our pleasure is further known."
When the Narnians realize that Rabadash won't let them leave the city unless Susan marries him, their first idea is to barricade the door and fight the entire empire with a total force of maybe ten guys, including a faun, a raven, and a ten-year-old. The only thing that puts them off the Last Stand is the prospect of the enemyburning the house down. Then the one who comes up with how they get themselves out of this particular situation and away from Tashbaan isn't King Edmund, the raven or the other humans, but Tumnus the faun - and it's actually a very cunning little plan too.