The yakuza in Act I thinking that Ginji is using a stun gun to electrocute them even when he clearly isn't holding anything.
Ginji: Yeah, a stun gun. One of those invisible kinds.
Ginji and Ban fighting over the pizza in Episode 1
Also, the sign Ban put on the door in episode 1 when he's getting a copy of the video surveillance.
Sign: No electric eels allowed!
In Act II: The Case Of The Lucky Cat Ban uses his evil eye to trick an overweight middle aged man into thinking a hot young girl is stripping outside his window. While this is going on Ginji goes inside to retrieve the ceramic cat and slips on a banana peel and smashes through the cats mouth, to makes matters worse the cat doesn't fit through the window and they break off more pieces in their futile attempt's to escape with it, and the evil eyes illusions were off before they can make a clean getaway. Finally N Atsumi tries to repair the cat for them before they deliver it to the client but damAges it even more.
Most conversations between Akabane and Ginji.
Ginji and Ban sneaking up on Kazuki in the hot springs, mistaking him for a bathing woman.
Any time Kazuki is forced to crossdress. Once during the hospital episode as a nurse, and the other when Ginji and Ban were trying to appease some teenage girl. Both times poor Kazuki had his masculinity mercilessly insulted.
One mission has Ban, Ginji, Shido, and Emishi team up to reclaim the missing arms of the Venus de Milo. They succeed and are heading home on the back of a whale Shido summoned (long story). The funny part comes while the other three banter, Ginji decides to take a look at the arms...and knocks them right into the ocean. Cue Ginji going Oh, Crap, while the other retrievers rise behind him, Death Glare included, promising pain...