Missus Crabapple, after Lisa questions the validity of the word ‘embiggens’:
“It’s a perfectly promulent word!”
Homer reading the side of a bottle after getting goofy on mixed cleaning agent fumes in the basement:
“na… myoho… renge… kyo”
and I especially love when Bart replaces all the hymnbooks in church with new songs, the pastor says,
“And now we will sing… ‘In the garden of Eden’, by I. Ron Butterfly…”
(Homer) “Hey Marge, remember when we used to make out to this hymn?”
I’m sorry, the word is cromulent. 
In the episode in which Homer gets fat in order to work at home on disability, he has to race back to the SNPP to shut off a valve on a tank lest it explode. The only way he can do this is to steal an ice cream truck. In this same ep, Mr. Burns is on a calisthenics trip and has all of the employees out on the PP lawn doing Iriquois Twists as Homer speeds by and they all turn to look and Mr. Burns’s perfect reply is: “There’ll be time for the frozen pudding wagon later!”
[Ralph]
They taste like burning!
[/Ralph]
I love this thread! I can’t stop reading it!
Thought of another one. In the Stampy episode when Homer falls into the tar pits.
Homer: “Don’t worry, I’ve got this under control. First I pull my legs out with my arms. Then I pull my arms out with my face.”
That kills me.
Oh, and a good throwaway I remembered last night. In the episode where Flanders becomes Homer’s best friend, Homer is ladling out gruel to the homeless people in the shelter really fast so that he can leave. A reporter sees this, and takes a picture, thinking it is a scoop. Later, on the front page of the newspaper, the headline is “Big fat man has big fat heart.” Underneath this, it says “Little skinny man accused in robbery.”
Also, one of the local hairdressers is called “The Perm Bank.”
“The fingers you have used to dial are too fat. To obtain a special dialing wand, please mash the keypad with your palm now.”
Homer: (to the melody of Tubthumping
I drink a whiskey drink,
I drink a vodka drink,
and when I have to pee,
I use the kitchen sink.
That keeps cracking me up.
Jasper John’s “You sqeal on me and I’ll kill you!” as he’s swiping some food is one of my favorites.
Bart and Lisa at the kitchen table, Bart saying “So I says to Mabel, I says…” then Homer interrupts and Bart says to Lisa “I’ll finish this later.” Totally out of the blue and great.
Kent Brockman reporting something totally pointless and then as he’s wrapping up he quickly adds “Oh yes, the President has been arrested for murder, more on that tomorrow. Or you can switch to another station… My producer is telling me to tell you NOT switch to another station.”
It wasn’t Lisa but a new teacher that questioned the word ‘embiggens’. She said something like “I never heard the word ‘embiggens’ before I came here.”
Later in the same episode the other shoe drops when the mayor states that Homers audition for the job of Town Crier was ‘cromulent’.
Homer: Hey Apu! Do you have any of those potato chips that give you diarrhea? I need to do a little spring cleaning.
Homer: That’s great Mister Burns! And I’m not easily impressed. Oh look! A blue car!
And this is officially the slowest newsday ever.
(does that count?)
The Stonecutters episode where Homer is trying so desperately to fit in with the guys so he can join. Lenny keeps spilling the beans and Carl keeps telling him to, “Shuuut uuuup.” Finally, at one point, Lenny blathers on one more time and Homer chimes in before Carl can and tells Lenny, “Shuuut uuuup.”
Homer: D’oh!
Lisa: A deer!
Marge: A female deer.
I think it’s from the Stampy episode.
It was Lisa’s teacher asking if “embiggins” was a real word.
The holloween episode with the giant advertising things attack. The doughnut guy goes back to Homer’s house after Homer accused Ned of taking the doughnut.
“I told you, Ned Flanders has it.” At that moment, you can see Ned running away.
The episode where Mod dies. In the dating video that Homer makes for Ned, when Ned is in the shower, one can tell that he is…um…“gifted.”
Sing to the tune of the Flinstones theme song
Simpson, Homer Simpson, he’s the greatest guy in history.
From the the, town of Springfield, he’s about to hit a chestnut tree
Really does crack you up, eh, photophat? 
Worst…er, best! use of double post ever.
More throwaways…
From Treehouse of Horror X, “Desperately Xeeking Xena”:
Frink: “In episode BF12, you are riding away on a winged Appaloosa, yet in the next scene, you are clearly riding atop a winged Arabian.”
Lucy: “Ah, yes…well, any time you see something like that…a wizard did it.”
Frink: "Okay, but in episode AF-
Lucy: “Wizard.”
Hehe, so perfect. And you can tell they’re really sticking it to the folks at snpp.com, god bless their little souls. But it really was pretty good.
Oh, and the Simpson Bible Stories episode is full of little moments. Like God/Flanders (why wasn’t he the usual God?) giving Eve some special interest magazines (People, with a picture of the only two people on earth).
Writers are discussing the character that will eventually become Poochie and this exchange takes place.
“We want him to be the original dog from hell.”
“Cerberus?”
Coming from a state with actual tar pits I’m obliged to say that I resemble that remark!
CB, glad you’re along for the ride. This thread is an effing gas!
In 22 Short Films about Springfield, when Marge is trying to get gum out of Lisa’s hair, I love it when the whole town somehow shows up to give their piece of advice. The best, though, is that the dancing baseball mascot (forget his name) just comes in and starts dancing, without giving any advice or saying anything at all (besides “Honk honk!”).
Also, I forget which episode, but the family is watching TV and they begin to talk about voice acting in cartoons, and suddenly Flanders shows up at the window, and in a completely different voice says “And you can change actors and no one will know the difference” or something like that.
Wasn’t a throwaway line, but my favorite Simpsons line:
At the end of the Beer Baron episode, Homer says, “To alcohol, the cause of, and solution to, all life’s problems!”
Kodos: I am Clin-Ton. As overlord, all will kneel trembling before me and obey my brutal commands. [crosses arms] End communication.
Marge: Hmm, that’s Slick Willie for you, always with the smooth talk.
– “Treehouse of Horror VII”