"Mr. Dennistein": The department store mannequin that PeeBee and Dennis bring to life takes their "have anything you want for lunch" request too literally and he reaches for the refrigerator bulb.
"Sounds of the Night": A policeman tries to arrest Henry but Alice mistakes him for a prowler and attacks him with a broom.
"Barber Shop Disharmony" has this exchange between Dennis and the mayor:
Dennis: How come you don't cut your own hair? Mayor: Cut my own hair? Dennis: Sure, my dad says you're great at trimming the public.
"Lights, Camera, Auction":
Dennis meets up with Mr. Wilson before he drives off to an auction.
Mr. Wilson: It's Mrs. Wilson's birthday and I thought I'd surprise her with something really cheap—I mean really pretty.
Followed by Dennis offering to come along to which Mr. Wilson objects. When Dennis plans on asking Mrs. Wilson what she wants that's cheap, Mr. Wilson puts him in the car without any hesitation. Dennis then gives a hilarious shrug and Aside Glance.
"Deserted with Dennis":
After Mr. Wilson lands on a deserted island and discovers Dennis in his suitcase, he says "I thought it was heaven, now I'm changing my mind!"
Then later on, Dennis accidentally drops coconuts from a tree. One of them hits Mr. Wilson's groin and he keels over.
"The Incredible Shrinking Dennis": A cat picks up a shrunken Dennis and prepares to eat him.
Dennis: Great. Now I won't have to marry Margaret.
Dennis accidentally triggering a huge pie fight in "Pie in the Eye".
Joey kisses Margret's doll's butt.
"Don't call me stupid, baby rump kisser!"
Dennis' ding-dong ditch on his babysitter and her boyfriend. The babysitter keeps accidentally bumping on her boyfriend's head.
Dennis trying to hold his laugh.
Mr. Wilson's Chiclet bucktooth.
The scene where Dennis’ Mom calls to tell Mrs. Wilson that her flight’s been delayed, resulting in Dennis having to stay for the garden party, and Mr. Wilson’s reaction.
Martha: Don’t worry about it. You get home when you can. We’ll be just fine here. Alice: What’s George gonna say? (Dramatic Thunder as we cut to) George: Over my dead body!
Mr. Wilson telling Dennis, in an eerily nice way, not to embarrass him in front of his party guests. He's obviously strangling the back of his neck and rubbed his hair too hard.
George:(in a sarcastically cheerful mood) Don't embarrass me!
This little dialogue:
Martha: George, take Dennis' suitcase up to the guest room, please. George: He's got arms. Martha: Don't start, dear.
Dennis asks George where he keeps the combination to his safe.
George: It's in my head. Dennis: What's that mean? George: It means I know it. I remember it. Dennis: What if you forget? George: I won't forget. It's a familiar number. I won't forget. Dennis: What's that mean? George:(getting irritated) It means it's a number I use all the time, so I won't forget!
It gets better when Dennis (who, may I remind you, is only five years old) immediately figures out what the combination is.
George sprays his nasal spray in his nose. But its full of mouthwash instead, and he screams like his brain is on fire! Then he dunks his head in the water to get the mouthwash out by blowing his nose.
Pretty much the entirety of Dennis' time with Switchblade Sam.
Dennis: I can't shut my mouth because my nose is stuffy. Switchblade Sam:SHUT UP!! [Dennis is quiet]
The face Gunther briefly made right before he ran for home.