Extremely high, especially in chapter 99: Ser Robert the Strong has Robb Stark's head!
Or how about chapter 97, wherein Aegon is revealed as a Blackfyre pretender, Jon Connington and Varys die, and two stone dragons are brought to life? Or if that's not doing it for you, maybe Cersei trying to destroy King's Landing with wildfire, Jaime killing her, and dragons advancing on the city in chapter 101 will. This fic arguably has a higher HSQ than A Storm of Swords.
Varys, Lady Nym and Tyene Sand for taking advantage of the miss-identification of a certain young queen at Riverrun and using it to bring down Houses Lannister, Tyrell, and Frey for Aegon Targaryen.
Sansa, for Recruiting the Brotherhood and Burned Men to her side, and managing to outmaneuver Littlefinger while being tried for Sweetrobin's murder.
What an Idiot: Oh sure Littlefinger, go ahead and weasel your way out of your undead and crazed former love's gaze by mentioning the Red Wedding. Don't forget to tell her that the whole thing was intended for Robb to be killed and for her to be ransomed back into your loving arms. Oh she might be offended, "Family Duty Honor" and all that, but she still loves you, right? This works as well as you would expect.
The Woobie: Many, many examples, but Edmure Tully and Jeyne Westerling easily stand out as the biggest ones. Edmure for having his plans botched of getting Jeyne to safety by Addam Marbrand, who sends a raven to Cersei who then promptly executes his lady wife and unborn child, destroying any leverage the Lannisters may have held on him, and Jeyne for her guilt over getting the man she loved killed by treachery, and then forced to abandon everything she knew and escape out of Riverrun with the Blackfish. Her family, along with Roslin, is completely wiped out because of her actions, leaving absolutely nothing else for her but the heir of the North growing inside her. And when she finally gives birth, the northern lords who had generally treated her well with hospitality soundly reject her after seeing that her son was born crippled because of the contraceptives she had unknowingly used.