These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
"He held the rank of a captain in the S.S. He was a black-uniformed strutting animal whose function in life was to give pain, and like his colleagues of the time he shared the one affliction most common amongst that breed known as Nazis: he walked the Earth without a heart."
He then proceeds to walk around his old abandoned concentration camp, thinking about the atrocities he committed and smiling as if these were the best years of his life! Don't worry though, he gets what's coming to him.
Hilarious in Hindsight: Set during World War II, "A Quality of Mercy" sees a lieutenant in the American forces sent back in a time by a few years and in the body of a lieutenant on the Japanese side. This main character here was played by Dean Stockwell, who would be on another show with a similar time travel concept about thirty years later.
Watching the future Captain Kirk losing his cool and going completely bonkers in "Nightmare at 20,000 Feet" is hysterical.
It Was His Sled: The endings of several episodes, the most famous probably being "The Monsters Are Due on Maple Street," "To Serve Man," "Nightmare at 20,000 Feet," and "An Occurrence at Owl Creek Bridge," although they've been put into spoiler tags for the sake of the few people who still don't know how they've ended.
"Time Enough At Last." Everyone knows what happens to Burgess Meredith. "No! There was time now!"
Recycled Script: Kept to a minimum for An Aesop anthology show. When it does happen, you'll frequently find that the moral of the story is a Family Unfriendly Aesop version of the previous episode's moral.
"Steel" is being adapted into a feature film. Though it's somewhat subverted, as Real Steel, despite being based on the same story as "Steel," bears almost no resemblance to the story (outside of robot boxers). Additionally, the film is decisively more optimistic than the original story's dystopian setting.
Seinfeld Is Unfunny: Perhaps the Ur Example. Just about every single episode has had its plot reused or redone by some sci-fi/horror show, movie, or book. Most modern viewers rewatching the series will often find themselves scratching their heads and asking, "How did people think this was scary? The story's been done to death." It's been done to death because Twilight Zone did it first. It really can't be overstated how explosively original (and at the time, controversial) a lot of the plots were, and the fact that they've since been repeated ad nauseum is a testament to The Twilight Zone's success as a show.
The Monsters Are Due on Maple Street. And then the same anvil had to be dropped again in the 2000's remake. Prejudice, paranoia, and hysteria can do your enemy's job alot better than the enemy can.
The episode He's Alive!, featuring Adolf Hitler as the mysterious advisor to a Neo-Nazi organization, may not seem to fit in this category today. Although, given that some four thousand people wrote in complaining about the portrayal of Hitler as a villain (more hate mail than any other episode triggered), it certainly fit into the category back then.
I Am the Night—Color Me Black is about the wrongful execution of a black man for a killing of a bigot in self-defense. The episode is clearly based on lynchings (and partially inspired by Emmett Till's death), features black men speaking from the voice of moral authority over white people, and heavily implies that many in the town don't care whether the man's guilty so long as they get to kill him. This episode aired in the final season in 1964, after the show's cancellation, and bare months before the Civil Rights Act of 1964.
Values Resonance: "The Monsters Are Due on Maple Street" supplies the page quote.
Writer on Board: Serling was an outspoken liberal, even for his day, and many of the show's recurring themes of corporate oppression, racism, censorship, isolationism, and the horrors of war were not simply ideas he liked to discuss, but the very reason he created the series was to use as a sounding board for such taboos.
Hilarious in Hindsight: In the "Good Life" segment, one of the characters is trapped in cartoon land. The character is played by Nancy Cartwright, a voice-actress then only a few years away from her most notable role. And just to hammer it home, the second "Treehouse of Horror" episode would spoof this story, with Bart as the all-powerful boy.
Tear Jerker: The "Kick the Can" segment can be considered this for some fans.
The New Twilight Zone (2000s)
Complete Monster: The older Anthony Fremont in "It's Still a Good Life." As a child, his actions could be understood as the petulant behavior of a child who doesn't understand what he's doing. He's not likable at all, but not purely evil. As an adult...
Fridge Brilliance: It's because he still has the mind of his child self, since no one ever was brave enough to teach him the consequences of actions as he grew up.