Hayate the Combat Butler/Funny

Since there are certainly a lot of hysterical moments within the series just list the chapter or episode number along with the example if you can, for at least some semblance of organization.

In volume 8. Tama (Nagi's pet tiger) has the idea to get Nagi's new kitten kicked out by tearing up her ~~picture diary~~ manga and blaming it on the kitten. While the title character tries to convince Tama to stop, the kitten actually does tear it up, and makes it look like Tama's fault. The kitten then goes from extremely cute to highly sinister, with a near full-page close-up and revealing its Xanatos Gambit with the telling phrase "Exactly as planned!" (or "Just as I planned!" in the official translation). The karmic payback is funny, but seeing Light Yagami reincarnated as a kitten is beyond words.
Nagi's idea of laundry. The obligatory demolition of the fourth wall makes it even funnier.
Wataru's^{[dead link]} statement about family after Nishizawa claiming they're like body soap.
Chapter 302 has several moments actually, which is to be expected when the plot is basically, Hayate trying to ask Hinagiku to live with him.
One that stands out is Hinagiku returning home after being frustrated over the whole situation only to walk into her house and find... Hayate getting permission from her mother for Hinagiku to stay at their apartment building. Hinagiku really shouldn't be so shocked considering that her mother adores Hayate.
Another comes after Hayate is incredibly close to getting Hinagiku to agree using a pretty heartfelt and very sparkly expression of how he likes being around her and to see her happy. Since the chapter isn't over and he isn't allowed to succeed yet, he completely fails when Hinagiku (incredibly flustered, mentions that it sounds like he's proposing. Hayate flat out says he was trying to sound like that. And that Yukiji told him to. What sells it is the beat panel right after where he seems to have actually realized his mistake right before the beating.
Adding to Mrs Katsura's contribution is her remark on the dangers of letting an adolescent boy and girl live together.

Mrs Katsura: Make sure you resist if Hina-chan attacks you, Hayate-kun.

In chapter 309, Isumi helps Sakuya "become a more interesting person" so that she can understand Nagi's manga. This "training" consists of having Sakuya don a giant penguin suit and dance around comically. Those who recall chapter 83 will note the karmic Brick Joke.
Chapter 310 focuses on Nagi's attempt to find inspiration for her manga.
- Alice relates to Nagi and Chiharu the story of being roused from her sleep the night before by a faint voice. The source of this voice was, in fact, a sleeping Hinagiku - who was writhing around and "breathing sweetly". When asked what sort of dream she was having, Hinagiku protests that she was merely ~~in heat~~ too hot.
- Chiharu asks Nagi what causes a tightness in her chest. Nagi's answer? After a moment of careful consideration... traps. She doesn't even wait a beat panel before calling out for Hayate.
Chapter 326: Nagi's moment of genre savviness

Nagi: "Oh, Hayate. What's wrong?"
Hayate: "Oh! Ojou-sama! Well, to be honest... um... uh..."
Nagi: "... You've done it again, haven't you?"
Hayate: "Yes, that's pretty much it..."

In the manga, one butler falls in love with Hayate, who at the moment is under a crossdressing curse. Although initially devastated when he finds out Hayate is actually a guy, he quickly comes around and tries to convince Hayate to travel with him to the Netherlands, where same-sex marriages are legal. (Cue Nagi's Megaton Kick.)
The following conversation:

Hinagiku: Now I'll never be a bride...
Ayumu: I'll take you.
Hinagiku: What about Hayate?
Ayumu: That's right... Then how about Polygamy?

In episode eight when Nagi makes Hayate cross dress so she can take photos, which works well since Hayate has a feminine appearance. It's already funny enough that Maria was watching. Then Tama, her pet tiger, sees Hayate in a cat girl costume. He ends up with hearts in his eyes, and then he pounces on Hayate, causing them both to fall out a window. Then Tama starts humping Hayate, complete with the show's man holding a sign that says "can't show" censor. Nagi even wonders if it's because he thought Hayate was a cute cat girl, or if he thought Hayate was a cute guy. It's even funnier if you know that One of Tama's hobbies is looking at male model magazines.
After season 2 Episode 12 you may never think of "Cruel Angel's Thesis" the same way again.
And let's not forget Klaus's flashback from back when he was a child. Klaus looked like a child with exactly the same face.
In one episode Hayate ends up dressed as a Catgirl maid by his employer. Naturally, the employer's pet white tiger, Tama, takes a liking to him, and, umm... yeah. The scene is censored, so we're not quite sure if it's actual rape or molestation, but Tama's certainly going through the motions there before Hayate knocks him away with an uppercut.
Chapter 304 reveals that Kotetsu has become a stalker to Hayate when he follows Hayate into the public bath and directly states Ho Yay as the reason why he is there and states that he loves Hayate. Hayate responds by trying to drown him.
Chapter 360 ends with - from Chiharu's perspective - an unconscious Hinagiku, in Hayate's room, on Hayate's futon, with said butler leaning over her. Chiharu makes the obvious assumption and - as the narration is more than happy to point out - she's technically right.

Narrator: Well, it is true he gave a girl something to drink in order to put her to sleep so that he could do something to her.

Izumi Segawa once walked across her butler (and big brother) Kotetsu confessing his feelings of love at first sight to a forcibly crossdressed Hayate (of course, not realizing that the Catgirl he was so attracted to was in fact a male). Izumi, knowing that Hayate was in fact male, told the two to "continue, and just don't mind me".