From what I remember, the Christmas special was still considered part of the Tracy Ullman Show. As for last night's episode, I laughed when Bart and Principal Skinner had the peanut/shrimp faceoff, especially at the end when they threw those things at each other.
I keep thinking the 1st episode of The Simpsons was the one where Bart goes to a school for gifted kids, which I always refer to the Kywjibo episode. Who remembers what a Kywjibo is? This had me rolling on the floor laughing when I first saw it.