From Radioactive Man:
"At last, the world is safe. Eh, Fallout Boy?"
"What's for lunch tomorrow?"
"Next."
"Chicken necks?"
^ Perhaps the best Wiggum exchange ever. And another fave in the same episode:
"Look behind you, Radioactive Man! The sun is exploding again!"
"Bart, what are you talking about?"
"Yeah, and who the hell are you talking to? Marge, do you have other men in this house? Radioactive Men?"
From Homer Alone:
"Hello, guv'ner! Lube job while you wait?"
"Don't touch me."
^ Classic double entendre.
From Simpson Safari:
"Start over! I want all the items in one bag."
"Yes, ma'am."
"But I don't want the bag to be heavy."
"I don't think that's possible."
"What are you, the Possible Police? Just do it!"
^ Even in the post-classic seasons, Agnes is usually pretty reliable for comedy. I love the way she says "Possible Police".
From Lisa the Skeptic:
"Your honor, over the coming weeks and months..."
^ I love how the lawyer openly admitted that the trial would waste months of everybody's time. It's not a joke that gets mentioned too much, but I love it.
From Homer's Phobia:
"So this is your sick mother?"
"Don't do this to me, Waylon!"
From Lisa Gets an "A":
"Nasty business, that zero. Naturally, Harvard's doors are now closed to you. But we'll pass on your application to... (snickers) Brown."
"Mmm, heck of a school. Weren't you at Brown, Otto?"
"Yup. Almost got tenure, too!"
From The Canine Mutiny:
"Well crying isn't gonna bring him back. Unless your tears smell like dog good. So you can either sit here and eat can after can of dog food until your tears smell enough like dog food for your dog to come back, or you can go out there and find your dog!"
^ Classic Homer string.
From Two Dozen and One GreyhounRAB:
"Ladies and gentlemen, this is the end. This... is the end of dog racing."
From The Last Temptation of Homer:
"Homer... I have a wicked idea that could get us into a lot of trouble."
"(worried) Oh, Mindy, we have to fight our temptations!"
"No Homer, let's do it. LET'S CALL ROOM SERVICE!"
"Oh."
^ A bit overexposed, since it also appeared in the second clip show, but still a great unexpected joke.
From Mobile Homer:
"Haw haw! People died in those shirts!"
^ One of my favorite Nelson "Haw haw"s.
From Mountain of Madness:
"Only who can prevent forest fires?" (Bart presses a button) You pressed "you," referring to me. That is incorrect. The correct answer is "you"."
^ A similar joke appeared in season 12's "The Computer Wore Menace Shoes"
From Simpson Tide:
"Milhouse, my mom wears earrings. Do you think she's cool?"
"No. I THINK SHE'S HOT! Sorry, it just slipped out."
From Realty Bites:
"I'm tired of being cooped up in this house all the time."
"Open a window!"
^ In fact, that whole exchange is amusing, such as Homer saying he already went to the azalea festival because Lenny really wanted to go, and his sarcastic "FrienRAB of the Library".
From The Haw-Hawed Couple:
"Who will spot the playful abalone? The mighty winkle? I think it might be you, Sherri." (Sherri gasps in excitement)
^ Love how excited Sherri is about looking for fish.
