Heck, any time Longmont Potion Castle shows up in a segment. When you hear that phone ringing, be ready to laugh.
The prank call in Conflict ends with the victim saying he's getting the police involved. As the next short begins, there is a brief animation of Longmont (portrayed by the Unabomber Speckles picture) getting chased by a stock-photo SWAT team.
The Dance episode has a whole segment revolving around people dancing around the streets of India while dressed as condoms.
The end credits of "Nightmares" play over a lengthy series of photos from Nightmares Fear Factory's Flickr account, depicting people getting spooked in a haunted house. Since they couldn't use and exploit the faces of random people, they are all replaced with hilarious substitute artwork. Highlights include four people with the "Unabomber Speckles" image (from the Longmont Potion Castle segments) for heads, two people with a stack of pancakes and a fishhead for heads, and three people whose heads are replaced with those of Space Ghost, Zorak, and Moltar.
If you look really closely, the airplane hits Space Ghost.
The "Crazy shit" short from "Love". It starts off with Daniel koren talking about all the amazing things we take for granted, such as gravity, which devolves into him listing random and/or mundane objects as completely over-the-top inspirational music plays.
"USB Stick! Coconut water! A boat!"
"A Family Affair" from "Liquid". It starts out as a very crudely animated short of a woman on the phone attempting to wash her cat. Then David Bowieshows up and steals her food.
The otherwise creepy "prebirth" scene in Sound takes a turn for the funny when one of the babies starts crying, which makes the alien panic and whip out keys to jangle to calm it down.