Pretty much all of these videos could be counted as Crowning Moments of Funny, but here are a few choice moments:
Medibot's Let's Plays:
Medibot's Let's Play of Kirby 64 is narrated in a soothing voice intended to keep the viewer relaxed. Then in one level, he finds some Invincible Candy and starts speaking in a demonic voice about killing and being indestructible. It is certainly Narm, but that's the idea.
Also, he fails to grab anything at the picnics several times in a row, and he clearly knows it.
After combining the Cutter and Bomb powers "And now this is the best power in the entire game. Because it turns Kirby into a ninja."
His reaction to the demonic King Dedede shows that he was clearly not ready for it.
One episode has an alternate commentary done by Illuminatus Vespucci, talking about Kirby as if he is a Humongous Mecha on a test run. He stumbles a few times, but gets a few good moments, such as complaining about the enormous cost of Kirby Mechs after Medibot dies.
"And when you combine cutter with the shock power, you get... Darth Kirby, Sith Lord. He fights for the Dark Side of the Force. He's extremely evil and has a doubled ended lightsaber." And seconds later, "But even Sith Lords love ice cream."
One tangent (one of the Woo-Hoo Hooniversity videos) is notable not only in that it's hilarious in its own right, but it's entirely displaced all discussion of what's actually going on in the video, which would itself be ripe for much hilarious postulation.
During the credits at the end, they make a plan for the Mushroom Kingdom to stage a hostile takeover of the Bean-Bean Kingdom.
Medibot plays Miriam Webster, who has a book for everything. Everything.
Episode 4 Act I: Kensington has just tried to steal some of the food that Miriam has cooked, and failed.
Miriam: Kensington, why are you always so sneaky like that?
Kensington: I don't know, let's roll for Stealth and find out. *rolls* I got a 21 for Stealth, so I'm just gonna go over here and you won't notice. *begins moving around the room*
Miriam: *rolls* I get a 22 Perception, I see you. *everyone cracks up while Kensington continues jumping around* Kensington, why are you running around the kitchen like a fool?
Episode 34 act 4: Medibot powerslides to an enemy, truly believing they have an overdue book cue:
Miriam: Are those your best moves there Monty three? You move around so wooden, thought you were a tree. Fat beats you can't drop it tunes you can't carry go and do so rhythm research at the local library. Now let me fill you in. Now let me give you a clue. I know you've got a book you've borrowed that's overdue. The book's not yours, it's the library's possession, that's why I'm here: to punish your indiscretion.
Shortly after, Miriam meets the real book thief, who decides to rip a few pages out of the book, in spite of the fact that she had witnessed aforementioned rap smackdown. Miriam proceeds to kill her. A lot. Namely by first hitting her a bunch for a large amount of damage, and then shifting her into a hell portal, in addition to the instant death caused by the thief being forced off the dance floor.