Probably “Mmmm…”, “D’oh!”, “Hah-hah” and “Excellent” the most, but I also will use
“Thank you, come again!” (Apu)
“I call the big one fighty.” (Homer)
“Disco Stu doesn’t advertise.”
“Who wants to hold new mommy’s hair while she vomits?”
“Okeleedokelee.”
There’s many more, but they come out as the situation arises.
How come nobody has mentioned comic book guy yet? Worst. Thread. Ever.
Around the office, if something pisses us off, we’ve been known to utter, “Stupid, sexy <fill in the blank…microwave, copier, coffee pot, boss>”
Stupid, sexy Happy
D’oh!
How could I forget the slick talking guy (he’s never been named AFAIK): “Oh, hey, a fat, sarcastic Star Trek fan. You must be a hit with the ladies, pal.”
And the happiest man in town: “No, not me, friends. He’s talking about himself. But thanks for noticing!”
Naturally, I have in all likelihood (LOL) over-used D’OH! 
And yes, I have actually used “Woo hoo! Four day weekend!” My daughter and I love Apu, though neither of us sound like him when we trade "Thank you, come again!"s 
“Excellent!” combined with rubbing one’s hands together suffices for a decent imitation of Mr. Burns, though. And the classic, “MMMMMMMM… <insert practically anything deliciously and decadently edible here> !”
We park our cars in the “car-hole.”
My blue Betta fish is named “Wiggum.”
I can’t keep track of all the sayings I use regularly.
Our current family favorite - saying someone is ‘a Viking’.
Ralph said, in some episode, ‘My dreams - that’s where I’m a Viking!’
That’s my all-time favorite, too.
What’s funny is that just about an hour ago, my boss smelled the new monitor we got (you know how new equipment smells when you first use it) and he accidentally said, “It sounds like burning.” I cracked up and said, “Oh my god, you sound like Ralph Wiggam!” Bwah!
“Do I know what rhetorical means?!”
I’ve used that one with great success.
I saw a license plate yesterday that sad DOH.
I could be wrong, but I’m pretty sure he calls the big one “Bitey”. Either that, or I’ve been hearing it wrong all this time.
[Jasper voice]
“Moon Pie… what a time to be alive…”
[/Jasper voice]
And three from Homer:
“SWEET MERCIFUL CRAP!”
“These doughnuts you speak of… are they real or symbolic?”
“Mmmmm… unexplained bacon.”
It IS bitey. That one was on last night.
Moon pies! I always say that whenever I actually buy/eat a moon pie.
My co-worker is big on “Excellent Smithers…”. I use Apu’s “Thank you, come again” too much, and “It tastes like burning” for anything not yummy.
We use a lot of the Comic Book Guy’s “Best/Worst. (insert word her). Ever.” in our house. Even my 5-year-old daugher says it. It’s a great thing to hear a little kid quoting the funnier aspects of The Simpsons.
A friend of mine and I are also quite fond of
HOMER: Bacon that sausage boy!
BART: But Dad. . .
HOMER: Bacon it!
BART: My heart hurts!
:smack:
Sorry about that.
Another one I’d like to add:
“If it’s yeller, you’ve got juice there feller. If it’s brown, you’re in cider town.”
Whenever I hear someone uses a curse word, I always bust out with, “Ohh, my freakin’ ears!” (Rod or Todd Flanders)
"It’s funny 'cause it’s true" (Fat Tony) always comes in handy when someone says something rediculous.
Of course, “Worst ____ ever” (Comic Book guy) makes it in to conversations all the time.
I think I use “Excellent” a little too much.
But my all-time favorite Simpsons quote/scene is:
(at the beach)
Homer: [to Pinchy] Relax, boy. We’re not gonna cook you! Enjoy your day at the beach. Ooh, look, here’s a little playmate for ya’.
(he picks up a snail and puts it in front of Pinchy. The snail bites Pinchy. Pinchy hides behind Homer’s leg.)
Hey! You don’t have to take that from no punk-ass crab! What’s wrong with you?
(Captain McAllister walks on)
McAllister: Y’arr, it’s not his fault he’s a sissy. (looks at Marge) Someone’s been coddling him.
Marge: Don’t look at me! I wanted to eat him!
McAllister: Eh, sorry, it’s usually the mother. Eh, y-you know, I run a small academy for lobsters like this one. We stress “tough love.” Daily chores and the like.
Marge: No! We’re not sending the lobster away to some snobby boarding school.
McAllister: Y’arr, I understand. It’s hard to let go. Eh, tell me this, then … do you have any spare change?
I just haven’t yet figured out how to fit in the “… do you have any spare change?” line into everyday conversations. But when I do, look out!
I always use “purple monkey dishwasher” whenever I need a random gibberish phrase.
Whenever removing my pants and there is sonmeone within earshot, I always use “must… drop… pantaloons…”
Also “Professional athletes - always wanting more”
“Homer no function beer well without.”
I like to substitue my name in for Homer’s
I also find myself calling a carport a “carhold” more and more often.
And maybe some of you Simpson gurus can help me out.
Wasn’t there an episode where Marge was giving Homer some
instructions to which Homer replies “Put the what in the what now.” Or something similar to that?
With my bro and I, whenever one of us is getting flustered/confused, like, “What [insert thing here]”, the other will respond with, “What bad things, why?” from the food critic episode.
We do the same thing when one of us says, “But- but- but,” following it up with “But the poncho!” “But the poncho! Hit the road, square.”
I typically slip in a “GLAVIN!” whenever I find myself casually discussing some piece of Trek trivia and betraying my own innate geekery.