The Alleged Computer: Subverted in "The Word Processor of the Gods". Writer Richard Hagstrom receives a homemade word plrocessor from his nephew Jonathan. The machine struggles with mundane text processing, but when it's commanded to rewrite Richard's life, the results are astounding. Especially with the last change Richard types up before it finally breaks down in flames.
The end of "Levitation". Just imagine... having the levitation trick done on you... only for the magician to have a heart attack, and can't bring you down... and prevent you from floating into the sky...
If there is a character the show doesn't want you to feel sympathy towards, when they get whats coming to 'em, then they usually fall under this category.
Back from the Dead: An interesting case in "Let the Games Begin": in order to settle who gets Harry's soul, the angel (in the form of Harry's best friend) and the devil (in the form of Harry's sister-in-law) resurrect his corpse in order to have him choose.
Be Careful What You Wish For: The episode "The Milkman Cometh" features a mysterious figure whose silhouette is shaped like a milkman granting wishes of anyone who leaves a note for him. The main character of the episode, a struggling father, begins to take advantage of the wishes despite his family and others who had their wishes backfire begging him to stop. At the end of the episode, he begs to the silhouetted figure to grant him a second child. While his face isn't shown to the viewer it's revealed that the Milkman isn't human and that the second child was conceived because the Milkman raped the wife.
Disproportionate Retribution: A hallmark of various supernatural beings on the series, but more so with a certain episode. "Halloween Candy" is a story about a rather grumpy old man who refuses to give out candy on Halloween. He is frightened to death by a malevolent being that he refused to give candy to. I know he wasn't exactly the nicest guy, but wow, killing someone for not giving candy?
Or how about the episode "Season Of Belief?" A couple have an extended Jerk Ass moment where they terrify their young children with a scary story on Christmas Eve, even getting another family member to play along with the joke. At the end they smile, say they were only joking...and out of nowhere, the very monster they were talking about appears and crushes their skulls. Okay, sure, the parents weren't being very nice, and told their six-year-old daughter there was no Santa, but did that really make them deserve to die?
Not to mention that their children are now orphans... very traumatized orphans. It really is disproportionate retribution all around (especially considering that the kids didn't even do anything).
Or how about the first episode "Trick or Treat"? An old man who holds the debts of pretty much every family in town offers to forgive everyone if their children can find their debts inside his haunted house on Halloween. The twist? He winds up in Hell for being greedy. Come on, he lived during The Great Depression, a time where everyone learned the value of a dollar. He just never dropped the habit of being very frugal with his money.
On the other hand, the jerk was having a lot of laughs scaring and taunting those poor kids half to death with his haunted house.
And he was pretty much of a loan shark, lording it over the rest of the town and setting terms the poor townsfolk (poor due to him, it should be noted) could never satisfy.
"Djinn, No Chaser": The genie has become a lot more nicer and complacent after being freed by means of a can opener.
"Word Processor of the Gods": Just before the titular device goes kaput, Richard manages to rewrite reality so that his nephew, Jonathan, is brought back to life... and is his son, along with Belinda (Jon's mother) being Richard's wife.
"The Spirit Photographer": Algernon was Dead All Along, but gets to move on after the titular device is proven to have worked. As a bonus, he's happy over this development.
Take That: "If the Shoe Fits". AKA: "The One The Equates Politicians to Clowns".