"Look at this country! U-R-Gay"
Edit: And not so much a quote on it's own, but Krusty the Clown's "What the hell was that?" after the Worker and Parasite show.
Carl,
"I think I've just logged onto my internet"
Homer (on hitting a deer): D'oh
Marge: a deer
Lisa: a female deer
Coincidentally heard earlier today in the office as a colleague was designing a poster with deers in it (on the cheap 😉 )
Toby, it's the bit just before that when he his searching for the peanut that makes me laugh.
Fishing under the sofa for it, 'hmm, hard. Hmm squishy. ARGH! MOVING!!!
'... and I owe it all to Yes I Cannabis'
Ralph, addressing Skinners boss - 'Super Nintendo Chalmers!'
When homer asks Burns what he wants for breakfast, Burns says 'a Dodo egg'
Marge, don't keep blaming yourself...
blame yourself once, then move on.
Mr Burns talking about one of his aging guard dogs,
"ahh, I'll never forget the day he bagged his first hippy, that young man didn't think it was too grooooooovy!" 😆
(Otto playing guitar loudly.)
Homer: Will you knock it off!? I can't hear myself think.
(Otto stops.)
Homer's Brain: I want some peanuts.
Homer: That's better
"Now I DRIVE the school bus"
Homer: Hey, I earned that money. While you lounge around here doing laundry and putting up drywall, I'm at work busting my hump.
Marge: Oh, please. From what I hear, you waltz in there at 10:30, take a nap on the toilet, then sit around Googling your own name until lunch.
Homer: (gasping) Who told you that?!
Marge: You shouted it while we were making love!!
"Everyone loves rats, but they don't wanna drink the rats' milk?"
Fishing under the sofa for it, 'hmm, hard. Hmm squishy. ARGH! MOVING!!!
Hah, I'd long since forgotten that, genius!
"Let the fools have their tartar(e) sauce"
I've never seen a brain freeze this bad. Give me 50cc's of hot fudge, stat! Hold still, you're going to feel a slight chocolately sensation.
Homer waiting impatiently behind someone @ traffic lights... " Green light Moron "
Mr Burns: "Why you're the fattest thing i've ever seen and I've been on Safari"
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Carmen Electra: My face is up here, Homer.
Homer: (looking at Carmen's breasts) I've made my choice.
"That's not a knife that's a spoon"
"I see you've played knifey spoony before"
Classic episode.
From the same episode...
Bullfrog? That's a stupid name! I'd have called them chazzwozzas!
Moll Flanders: We're not talking about 'love' here Edna, we are talking about S-E-X in front of the C-H-I-L-D-R-E-N!
Krusty (suddenly paying attention) SEX CAULDRON?! I thought they'd closed that place down!
Some genius ones up there I haven't seen, love the bunny faces on the outlets one 😀
Poison....poison.....tasty fish!
And
Trampopoline!
If something's hard, then it's not worth doing.
Tramapaline +!
Homer: Hello… My name is Mr. Burns. I believe you have a letter for me.
Clerk: Okay, Mr. Burns, uhh, what’s your first name?
Homer: I don’t know…
&
Space coyote: Find your soulmate, Homer. Find your soulmate.
Homer: Where? Where?
Space coyote: This is just your memory. I can’t give you any new information.
Milhouse: I thought you said you could read lips
Bart: I assumed I could
[i]Springfield enclosed in a big dome to contain the pollution...[/i]
We're trapped like rats!
No, rats are too intelligent to be trapped that easily; you're trapped like...... carrots
Heh clown college! How could I forget?!
"it's just a little airborne it's still good it's still good"
'Mmmmm forbidden donut... Sacrelicious'
From the episode where homer is trying to get fat enough to be classified as disabled, some advice from Dr Nick "You'll want to focus on the neglected food groups. Such as the whipped group, the congealed group and the chocotastic!" and "if you’re not sure about something, rub it against a piece of paper. If the paper turns clear, it’s your window to weight gain."
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Homer: "Bart, never forget you are special. Just like everybody else".
Might have exact wording wrong, but use of it got my son to 16 with good results!
Homer when meeting with aliens
"Don't eat me, I have a wife and kids"
"Eat them"
Apologies if I misquote...
Marge: Will he be okay?
Dr Hibbert: (his trademark laugh then...) He'll be okay. Not you and me okay...
"Look at this country! U-R-Gay"
Love it - use that whenever U-r-gay comes into a conversation. Unfortunately a) it doesn't very often and b) the reference is invariably lost on everyone else.
Not a quote, but this clip still cracks me up every time
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And, of course, "Stupid sexy Flanders"
The suspects are wearing hats, repeat wearing hats - Chief Wiggum.
D'oH! 
operator give me the number for 911
Mmmmm Elephant fresh.
Ahh, Squiddey. I don't hate you. I just heard there's gold in ya belly!
Not that great but stuck in my head for ever.