Fix, a relatively small, frightened man, beating the crap out of the Winter Knight, one of the most horrible beings in the Winter Court (and, in fact, the whole series), with a wrench. All because he hurt his friend.
Harry not only resisting the temptations of the Winter Lady (by pouring ice water on his crotch) but also verbally bitchslapping her by saying that she couldn't have murdered the Summer Knight because not only is she not powerful enough, but she's also an immature, impulse-driven child.
Although not shown, Simon Petrovich wiping out most, if not all, of the vampires that atttacked Archangel with his Death Curse.
Meryl making a Heroic Sacrifice, Choosing to become fae so that, with a last burst of troll strength, she can take down the Lord Marshal and save Harry, who in turn turns the tables on Aurora and saves Lily.
A stealthMoment Of Awesome for the villains: when Harry jabs "Mr. Grum" in the arm with an iron nail, the undercover fae not only recovers from what must've been excruciating pain in a matter of seconds, but has the speed of glamour-casting and the presence of mind to adopt a second disguise before Harry can glance up at his attacker. Pretty fast save by Lord Talos, there.
In a diplomacy-based example, seeing our first glimpse of how the Gatekeeper quietly and deftly steers the Senior Council onto what he knows is the right path, even if they don't have a clue what's going on, scores a big one.