Base Breaker: Post-season 6, the fans are split into roughly equal camps: those who want Aoefel back and those who never want to see him again. Even during his tenure as The Intern, opinions were equally polarized.
Crosses the Line Twice: Jim's treatment of Jeff, the head of the Baldur's Gate chapter of Acquisitions Incorporated. Specifically, tricking Jeff into thinking he has magical powers and leaving him to defend the chapterhouse's foyer against an army of bad guys. Chris takes a moment to really rub it in:
Jeff: I feel so empowered! Jim: I... believe in you. Jeff: Have a magical day, Jim! Jim: You too, Jeff! Jerry (out-of-character): That makes me feel sick.
Where did Omin's second sister come from all of a sudden in season 9? She's actually Jerry's invention, just like Portentia! Chris introduced the latter based on a story Jerry told in season 4, but when Jerry didn't remember it himself and invented a whole new story on the spot, Chris did the exact same thing again and made that second story canon, too!
Viari's two main ordeals in season 9 finale were a stealth comeback by Chris for all of Pat's rules-lawyering earlier! Think about it: first, Chris brings back Danielle the Drow, the only other notable rogue in the series thus far, who basically out-rogues Viari by pulling the same Affectionate Pickpocket trick on him that he used on Vannifer (and it takes Pat a full ten minutes to realize that and check his possessions!). Then, the falling beholder tank is essentially the Falling Chandelier of Doom trick that Viari pulled on the Viper and his men in season 7, but in reverse!
Ho Yay: Between Aoefel and Binwin's fondness for each other, Binwin's claims of being "legally married" to Jim, Omin's suspicious possessiveness of "James", and Viari's Homoerotic Dreaming about Drizzt, there is a lot of it on this show.