*Rod Serling voice* You’re traveling through another dimension…
"Where Is Everybody?" (Season 1, Episode 1, 1959)
Good if you like: Westerns, mysteries, last man on Earth, slowly going crazy
The very first Twilight Zone episode features a man who finds himself completely alone in an otherwise seemingly active town. With themes of isolation and human psychology and a twist ending, it's a great introduction to the overall feel of the show.
CBS
"Time Enough At Last" (Season 1, Episode 8, 1959)
Good if you like: Irony, last man on Earth, simplicity
This classic episode follows an unhappy man who really just wants time to read, and his wish is granted when he's the sole survivor of a nuclear war. The ending will leave you groaning in frustration (in a very good way).
CBS
"The Monsters Are Due on Maple Street" (Season 1, Episode 22, 1960)
Good if you like: Mob mentality, small-town psychology, heavy morals
This one is also known by many high schoolers as the script they had to read to learn about the dangers of mob mentality, and it's a good lesson. Watch these townspeople tear each other apart trying to guess who's the impostor among them.
CBS
"The After Hours" (Season 1, Episode 34, 1960)
Good if you like: Alfred Hitchcock films, thrillers, happy endings
If you've ever been creeped out by those full-body mannequins in a clothing store, this is either the best or worst episode for you. A woman gets trapped on a deserted department store floor and is treated very oddly by the clerks.
CBS
