They’re dogs!
And they’re playing poker!!!
“super fun happy slide!!”
“But the football…his groin…it works on so many levels!”
“Do I know what rhetorical means?”
Donuts … is there anything they can’t do?
Possibly my personal favorite, as my friend has nicknamed her cat after this quote.
“I call the big one Bitey.”
From the Pinchy episode
Bart: Can we have some?
Homer: sniff sniff… no, Pinchy would have wanted it this way
and from the leporasy episode
Brains… Brains… You can use your brains to help us out. Your sweet delicious brains.
Hmm. Don’t seem to recall that Homer line, and I can’t Google it either. Cite? 
“Are you tired of having your hands cut off by snowblowers?” -Homer
“Mr. Plow, that’s my name. That name again is Mr. Plow.”
can be heard here:
“Come to Homercles!”
“We’re number one! We’re number one! In your face, space coyote!”
“Let’s get Homer-erotic!”
“Homercles cares not for beans!”
“C’mon Marge, take off the babmababushka!”
Homer IOU one donut
signed Homer.
Homer: I can’t believe my little boy is going on his very first date. Sunrise, sunset. Sunriiise, sunset. And the cat’s in the cradle and the silver spoon, yes, we have no, bananas… (sniffling)
Marge: Ah Homer, that’s sweet. Our son is growing up isn’t he?
Homer: No it’s not that! Didn’t you hear? They have no bananas! They have no bananas today! (runs off crying)
Oh I forgot!
In the episode where they join the witness relocation program to get away from sideshow Bob…
Bart is in bed in the dark, looking very tense…
Homer: (screaming and brandishing a butchers knife, with red eyes and a dark figure) BARTDOYOUWANTABITOFBROWNIEBEFOREYOUGOTOBED!?
Bart: AHHHHHH!
Homer: Come on, let me cut you a piece of brownie.
Bart: Dad, I’m a little edgy right now. It would help if you didn’t come screaming into my room waving knives.
Homer: Oh, what was I thinking. (kisses Bart and leaves)
Homer:(Almost immediatly coming back into the room, screaming and waving a chainsaw.)
BARTDOYOUWANTTOSEEMYNEWHOCKEYMASKANDCHAINSAW!?
Argggh damn coding! Preview preview preview!
“Don’t blame me. I voted for Kodos!”
Oh Lisa! You and your stories! Bart is a vampire! Beer kills brain-cells! Now lets go back to that…building…thingy… where our beds and TV…is.
every time I learn something new, it pushes some old stuff out of my brain. Remember when I took that home winemaking course, and I forgot how to drive?
What is a wedding? Webster’s Dictionary defines a wedding as “The process of removing weeds from one’s garden.”
I know you can read my thoughts, boy : Meow, Meow, Meow, Meow, Meow, Meow, Meow, Meow, Meow, Meow, Meow, Meow, Meow, Meow, Meow, Meow.
I’m in a place where I don’t know where I am!
Operator! Give me the number for 911!
They have the Internet on computers, now?
Uh huh. Uh huh. Okay. Um, can you repeat the part of the stuff where you said all about the … things? Uh … the things.
Wait a minute. I’m a guy like me!
Clown college? You can’t eat that.
Later on
That’s it! You people have stood in my way long enough. I’m going to clown college! /leaves
Bart: I don’t think any of us expected him to say that.
“Homer! There’s no air in space!!”
“There’s an Air & Space museum”