"Be Our Guest" was hilarious on its own, especially all the torment Cogsworth went through, but one line in particular is especially hilarious.
Cogsworth:(almost in sync with the music whilst a group of featherdusters are dancing ever closer to him) Oh, gee, darn. Fun's over. Over here. (realizes they're not stopping) Line up, now! Aaaahhh! (runs for it)
Belle's conversation with Lumiere and Cogsworth (after she has been treated to a production number by a singing candlestick and a veritable platoon of dancing tableware):
Belle: I couldn't possibly sleep now! It's my first time in an enchanted castle! Cogsworth:(laughing nervously as a fork skitters by on its tines)Enchanted? Who said anything about the castle being enchanted? (to Lumiere) It was you, wasn't it?! (they fight) Belle: I... figured it out myself.
The Beast is trying to think up something nice to do for Belle. Cogsworth brainstorms: "Well, there's the usual things: flowers, chocolates, promises you don't intend to keep..."
Bonus points for that last part being a Throw It In ad-lib by David Ogden Stiers.
The porridge-eating scene. Beast trying to eat with a spoon is hilarious!
Beast getting his hair cut for the big dance scene. First time it's finished:
Lumiere: Oh, you look so...so... (struggling to find the word) Beast:(completely deadpan with an over-the-top hairstyle) Stupid.
Gaston: Here, picture this: A rustic hunting lodge, my latest kill roasting on the fire, and my little wife massaging my feet, while the little ones play on the floor with the dogs. We'll have six or seven.
The hilarious facial expressions Beast makes when he and Belle are arguing about her running away, especially when he's positively dumbfounded that she's telling him off and can't think of anything to say.
Beast: If you hadn't run away this wouldn't happen. Belle: If you hadn't frightened me I wouldn't have run away! Beast:(lost for words) ...Well you shouldn't have been at the west wing! Belle: Well you should have learned to control your temper!
Pretty much all of 'Gaston', but especially the lyric "I use antlers in all of my dec-o-rating!" and the accompanying visual.
These lines after throwing Maurice out of the tavern;
Gaston:La Fou, I'm afraid I've been thinking.
La Fou:A dangerous pastime-
Gaston pausing while proposing to Belle to check out his reflection in the mirror. And the fish eye effect of him when Belle peers out the door to see who it is when he comes to her house to propose.
There's also Belle rejecting Gaston by opening her door and letting him fall into the mud head first with his butt sticking out after saying "I just don't deserve you!"
Even funnier in the stage version, where he responds to this with "Who does?" This is after a song where he says that women are "occasionally" useful "mainly for extending the family tree", and that "we will be the perfect pair, rather like my thighs".
The Bimbette's crying at Gaston's "wedding" ceremony for Belle because they are in love with him.
What makes it is the contrast to what happened beforehand; Gaston thanks everyone gathered for coming to the wedding reception he's set up in front of Belle's house, and adds jokingly, "But first I'd better propose to the girl!" which makes everyone laugh. Cut to the Bimbette's.
The Bimbette's "accidentally" spraying Le Fou with water after he goes gaga over them.
After the song "Something There", Mrs. Potts doesn't want to answer Chip's question.
Mrs. Potts: [singing] There may be something there that wasn't there before.
Cogsworth telling the Beast that Belle isn't coming down to dinner.
Beast: Well? Where is she? Cogsworth: Who? Oh, the girl! (starts getting nervous) Yes, the...girl. Well, actually, she's in the process of, uh...circumstances being what they are...she's not coming. Beast:(after a beat)WHAT?!
Anything with Gaston when he's not being sadistically creepy. Something about his ego and the way he talks with pride over the assumption that if he wants something then he deserves it is hilarious.
Funniest part is this after LeFou makes fun of her father:
Belle: Don't talk about my father that way!
Gaston: Yeah! Don't talk about her father that way! (bonks LeFou on the head)
His first line in the movie. It's so transparently assholeish that it's just hilarious.
LeFou: Whoa you didn't miss a shot Gaston. You're the greatest hunter in the whole world.
Gaston: I know.
There's also the line from the commentary: "If you scratch your DVD cover, you can take a whiff of the Beast's room!"
The Beast's face when Belle leans on his chest during the ballroom scene, as well as Cogsworth's and Lumiere's reactions
"Mama, do I still have to sleep in the cupboard?"
The adorable look on Chip's face when he asks makes it even better. Even his mother giggles!
Gaston grabbing Belle's book and asking how she can read it when it doesn't even have any pictures. Made funnier by the fact that it actually does have pictures, it's just that it's an illustrated storybook with a lot of text.
LeFou standing to the side and singing "Kill the Beast" as the villagers are ramming down the castle doors.
Le Fou conducting the band
Gaston: "Now when Belle and I come out that door-
Le Fou: "Oh! I know! I know! I strike up the band!"
*cue fast tempo version of "Here comes the Bride" which is then Cut Short by Gaston throwing a tuba on Le Fou's head*
Gaston: "Not yet!"
Le Fou: "Sorry"
It's shown that he's still conducting the band after Gaston is thrown into the mud.
Le Fou: So, how did it go? Gaston:(grabs Le Fou by his shirt) I'll have Belle for my wife. Make no mistake about that! (Gaston throws him on the mud) Le Fou: Hmm, touchy! Pig:(agreeing with Le Fou) *snort, snort*
During Belle and the Prince's dance, Lumiere and Cogsworth get into a fight each claiming he was the one who knew it would work out in the end. Clearly Cogworth was mostly skeptical during the film.
Lumiere: I told you they would break the spell! Cogsworth: I beg your pardon, old friend, but I believe I told you. Lumiere: No, you didn't. I told you! Cogsworth:(pushes Lumiere) You most certainly did not, you pompous, paraffin-headed peabrain! Lumiere: En garde, you... you overgrown pocket watch! (slap his face with a glove)
During 'Something There', Belle ducks behind a tree while the Beast feeds some birds, in order to get a gauge on the sudden new feelings she has about him. She peeks back around the tree - to find him with birds perching all over him.
In the stage play, Lumiere and Cogsworth are commiserating over the prospects of being cursed forever, when Belle arrives and passes by looking for Maruice. The following exchange is often played as such:
Lumiere: Oh, it's a girl. Cogsworth: I can see it's a girl. (Beat.) (Double-take.) Both:It's a girl!!!