Hilarious in Hindsight: In the Darker and Edgier opening sequence, Homer gets hit by Marge in her car. The show's HD opening, introduced in season 20's "Take My Life, Please", now has Marge accidentally hitting Homer in her car.
Nightmare Fuel: During "The Terror of Tiny Toon", Bart is reduced to a skeleton by a stream of piranha coming out of a fire hose.
One-Scene Wonder: Krusty appearing in vampire getup to host the Itchy and Scratchy segment of "The Terror of Tiny Toon". Reached Ensemble Darkhorse status considering how that incarnation of Krusty became a Burger King Halloween toy and appeared in some Treehouse of Horror merchandise and imagery, despite not really playing a role in the segment.
Ugly Cute: Maggie when she transforms into an alien.