The pain monster sure is one of my favs. Also a character well underrated (e.g. I couldnt find him as a profile pic). He might not have much on-screen time but his concept is sound and he delivers. Yet covid postponed the Tax day from 15th april to july 15 - posing the question whether that means more or less work for him?
Just as important to note is the Being of inconceivable horror. They own the milky way but almost nobody takes that into account in their daily decision making. Or did ebay in the end fail to accept their choice of payment? What were their long term motives? And did they/she/he chose the name willingly or was it given to them by someone else?
Another all time fav. is Mr. Peppy, also due to his unlikelihood. That innocent bone vampire was really lucky that leela had a bone in her froot cup
Potentially provoking a vegetarian/vegan dispute whether eating bones will clearly make you a carnivore..
Another top 4 for me and secret number one is Lrrr. Just everything makes him awesome, his emotional imaturity, his love for animals and his gorgeous palace which leaves room for exactly one 15inch tube TV. If anyone is up for travelling to the actual star system omicron persei to check if he's there I'm all in :]