I'm not sure what this dub of Po Pi Po is making fun of, but the person who did it just sounds so ANGRY when he does it that it's frickin' hilarious. YMMV on this one, though.
Hey Master, did you buy us thinking we were an eroge? I'M RIGHT, AREN'T I?!
We also have Rin Chan Nau! done by Owata-P, in the same vein as the song above. Features Miku and Luka and their crushes on Rin.
Luka's Creepy Toast and Sonika's Creepy Song, both parodying how many twisted Vocaloid songs there are. Especially Creepy Song, which specifically makes fun of all the songs where the vocaloids are killed.
Then there's Big Al's gag dub, which changes the theme to being pissed about couples doing too much PDA in school.
I've dubbed Luka's version and Big Al's version myself (lyrics slightly changed to fit a girl online and a college girl respectively). Anyone wanna see?
The "Temptation of M" drama series (part 1/part 2/part 3). Features exhibitionism, apparent genderswaps, Miku trying (and massively failing) to be sexy, a number of unexpected cameos, and some of the funniest dialogue, sight gags, and characterization in any Talkloid project.
If Lily Was Like This... Another entertaining character piece, spotlighting the (at the time) new character of Lily. As with "Temptation of M" above, one of the funniest things about it is how good the acting is — it's hard to imagine how much fine-tuning it took to get the character's voices to sound natural.
Leon attempts to sing Love is War. But then Kaito hears him sing "I scream (Ice cream) for you..."
Your Mileage May Vary, but in Madness of Duke Venomania, Gakupo's expression after he finds out that Kaito isn't a girl is HILLARIOUS. Seen here, at about 3:24.
Also, if you look closely at the second missing persons list, you'll see that one of the missing women is actually Rin's horse from Daughter of Evil.
Leon: Tsunderes in anime are okay/But in real life it's just a bitch.
Rin and Gakupo play a practical joke on Miku on her birthday with a present whose lid was sealed so tight it would snap open. Rin's giggle and Gakupo's laughter after Miku got smacked in the face were a riot.
Haku's Drunken Afternoon - a silly skit (with an equally silly soundtrack) about Haku Yowane just being completely wasted from all her drinking on a fine sunny afternoon, during which she starts seeing Rin and Len somehow flying in the sky above, much to her disbelief. Meiko arrives wondering what the fuss is all about, and makes the obvious conclusion that Haku in her drunken stupor was just seeing things.
This MMD video of Big Al, Kiyoteru, Leon, Kaito, Tonio, and Gakupo singing and dancing to the famous internet sensation Yatta! by the Fake Band Green Leaves. Perhaps the only thing that can top this would be an actual vocaloid cover of the song.
. Takoluka goes for a bath in an onsen...and comes out as steamed octopus.
The bridge of the music video of the cover of Asereje (The vocaloids sing in nearly fluent Spanish, too!), where Kaito and Len appear in swimsuits and dancing like the girls, and when four hands try to grope Miku's butt. Of course, Your Mileage May Vary on this one.
And later when she identifies her granddaughter from this very complex. When she's "comforting" her on this ("On the bright side, they make you look fierce!") is hilarious as well.
This talkaloid featuring a depressed Luka, a racist Sweet Ann, and Big Al (who's just trying to keep them together).
Then we've got this lil' ditty. And as if that wasn't cute enough, there's this!
This dialogue between Kaito, Gakupo, and Kiyoteru in a karaoke bar, where the fun loving Kaito and Gakupo try to get a very straight-laced Kiyoteru to loosen up. At one point Kiyoteru is made to sing the Cutey Honey theme (with the expected reaction of embarrassment from him) by the other two (though Gakupo joins in singing after a moment). Kaito and Gakupo also try to make Kiyoteru sing Koi no Kayoubi (a song which features Kiyoteru crossdressing, hence he quickly refuses). Kaito then tries to sing Boo*s are Man's Romance with the hopes of getting Kiyoteru to shout Oppai!, an effort also shot down by Kiyoteru. Finally Kaito sings Ne~e? and gets the other two laughing at him.
Miku sings Sons of Skyrim, with a montage of her trying and failing to be a Dovakin.
This is a hilarious sync of World's End Dancehall with the video of I Want To Love You Tender from Armi Ja Danny, which gained some infamy (read: intense mockery) for being a ridiculously low budget music video.