Sorry, you forgot the best quote from the episode: Bart: Christmas is a time when people of all religions come together to worship Jesus Christ!"
My favorite episode of all time has to be The City of New York vs. Homer Simpson. At the end, Homer is driving what's left of his car out of the city with his family. Lisa asks: "Dad, can we come back next year?" Just then, a garbage truck driving in front of them hits a bump and a bag full of medical waste goes straight through Homer's shattered windshield and explodes all over his face. Homer: "We'll see, honey. We'll see." Kills me everytime. A few other favorite moments: Homer: "When I held that gun in my hand, I felt a surge of power…like God must feel when he’s holding a gun." Homer: "I’m normally not a praying man, but if you’re up there, please save me, Superman." Homer: "Fame was like a drug. But what was even more like a drug were the drugs."
For those of you interested in various bits and pieces of Simpsons trivia, check out the commentaries for each episode in the DVD box sets. There's one for every episode (at least for seasons 3 through 8 which are the ones I own) and some of them are just hilarious in themselves. Anything commentary with Jon Lovitz is almost better than the episode itself. For example, you can find out such gems like the following: Matt Groening's design for both Homer and Krusty is based around the idea that Bart worships this clown who looks almost identical to Homer, but has no respect for his father.
My favorite has got to be the episode where Homer purchases his gun. So many amazingly good lines in that episode.
Two particular scenes get me every time. I may be off on the exact wording but you get the idea: 1. The one where the Power Plant employees go on strike. Homer's at the union meeting and they vote to get rid of the dental plan, but the voice of Marge in his head reminds him that Lisa needs braces. "Dental plan." "Lisa needs braces!" "Dental plan." "Lisa needs braces!" "Dental plan." "Lisa needs braces!" "Dental plan." "Lisa needs braces!" All of a sudden somebody drops a pencil down Homer's exposed ass crack. Homer: "Hey, I lost my train of thought! Now where was I?" (He immediately goes back to the thoughts in his head with the same dumb look on his face.) "Dental plan." "Lisa needs braces!" 2. Homer goes to the freezer and opens a box of Neopolitan ice cream. "Mmm, chocolate." (Sees that the vanilla and strawberry are untouched but the chocolate has been eaten.) "D'oh!" (Opens another box of Neopolitan ice cream.) "Mmm, chocolate." (Again, sees the chocolate is gone but vanilla and strawberry remain." "D'oh!" (Picks another box of Neopolitan.) "Mmm, chocolate." (Same result.) "D'oh! Marge! We need more chocolate, vanilla, and strawberry ice cream!" MARGE: "I'll pick some up at the store." HOMER: "Mmm, chocolate."