Burt holding the return policy of his nice shirt hostage on picture day.
Maw Maw getting fed up of being quarantined in "The Sniffles".
Burt: "There's a predator in your neighborhood. *cough* It's me."
That whole montage, and the scene at the end.
Burt getting freaked out by the computer. On it's own, it's funny. But it's hilarious when you remember that Dillahunt use to play a Terminator. Likewise when he gets snarky and snarks about going back in time to change events.
Burt trying to get Maw Maw to stop smoking. She immediately puts it out—on him.
All three of the possible ads for Howdy's Supermarket in "Baby Monitor"
The spitting contest between Burt and the alpaca in "Don't Vote for this Episode"
Also in that episode, when Kenny is convinced his store has a gypsy.
Maw-Maw hears the rest of the cast up in the attic, and starts shooting.
Maw-Maw: "I hear you up their, mongooses!"
Virginia: "We're not mongooses!"
Maw-Maw: "That's just what a mongoose would say!"
The very beginning of "Sabrina Has Money", when Burt is told that the rich guy whose pool he's cleaning is Sabrina's father. He just keeps looking around and stammering in utterly adorable bemusement for about twenty full seconds before the scene cuts away.
Burt yells at a lobster he bought...then immediately apologizes to it.
Everything about the Japanese toilet.
Virginia: Burt...are you jealous of a toilet? Burt: Of course I am!
When Burt shows Hope the picture of her mom in the electric chair, Hope smiles and laughs.
In "Henderson, Nevada Adjacent, Baby!" Sabrina says that Jimmy doesn't seem like the Vegas type.
Jimmy: That's because you only really know Daddy Jimmy. You don't know sex-in-the-back-of-my-van-with-a-serial-killer Jimmy. I used to be a wild man before this little ball and chain came and threw a wet blanket on my party fire. (Hope does something cute.) She is cute, though, isn't she? (devolves into Baby Talk)
Sabrina: You need to party.
Jimmy: Oh, I do.
Also in "Henderson, Nevada Adjacent, Baby!", the montage of Virginia trying to decide whether or not she should go to her terrible cousin's wedding, interspersed with Burt whittling an entire tree branch down to a toothpick.
The unfortunate soul who decided to video chat Maw-Maw. A naked Maw-Maw.
The fact that he later shows up for a date makes it even funnier.
Burt thinking Frank's killed Jimmy, and enters the house to catch Jimmy playing with dolls of himself and Sabrina.
Maw-Maw's series of ideas that would have been amazing 30 years ago. The best is how she comes up with the idea of a 24-hour cable news channel, then immediately dismisses the notion because she thinks it would lead to programs full of pundents just to fill time, which leads to partisan bickering, and thus is a terrible idea.
Opening scene in "Spanks Butt, No Spanks" Jimmy gives Hope her bowl of oatmeal, she throws the spoon at him and giggles. He tells her "Very funny, Hope, but you need your spoon to eat your oatmeal." Hope's response: No! *pushes bowl off table.*
Maw-Maw: I haven't gotten a speeding ticket since 1962. Your about to find out why.
Maw Maw getting a lap dance from the pizza guy who they thought was a stripper.
Jimmy: Why are you getting a lap dance from the pizza guy who I went to high school with?
Pizza Guy: Come on, gimme a chance.
Maw Maw: Quit staring. It's getting awkward.
A lot of "Jimmy & Sabrina's Wedding"
Burt and Lucy's father subduing her in the back room, with no one aware of what happened. One of the funniest visual gags was them trying out the shock collar to see if they could hear her scream. As it turns out, while she didn't scream she was one of the statues behind them in the frame.
The wedding cake disaster being treated akin to an oil spill.
The entirety of "Murder, She Hoped." It is a spot on parody of Alfred Hitchcock films, not only the basic plot of Rear Window but the acting, direction and framing evokes his entire library of films.