* BizarroEpisode: "Controlled Experiment" is an oddball of the original series due to its unusual comedic tone. This is explained in part that it was never intended as an ''Outer Limits'' episode in the first place, but was really a [[PoorlyDisguisedPilot rejected pilot]] for an unrelated half hour sci-fi series.
** The series' first season had impressive orchestrated scores, especially for episodes like "The Galaxy Being" (which created music cues frequently used throughout the series), the transformation sequence in "The Sixth Finger", and whenever the telepathic power manifests in "The Man With The Power".
** And the heart-wrenching, inspiring music that plays in the last scene of "A Feasibility Study" [[spoiler: as everyone in town joins hands to perform a HeroicSacrifice.]] It got reused in a couple of other episodes, too.
* FirstInstallmentWins: The revival may have lasted much longer, but the original series seems to be the one most people remember.
* HilariousInHindsight: "Production and Decay of Strange Particles" has a character played by Creator/LeonardNimoy getting killed by radiation--18 years before ''Film/StarTrekIITheWrathOfKhan''.
* NarmCharm: Some episodes run on this, most famously "The Zanti Misfits", where the antagonists are oversized alien ''ants'', but the actors play the terror of the scenes so perfectly straight in spite of that, that it made the episode a cult classic of sorts.
* NightmareFuel: You would think all the dated costumes and special effects would look silly in the present day, but some of those monsters can still freeze your blood. Robert Culp gets transformed into a space creature in "The Architects Of Fear", and the flashes of his gradual changes are shocking to see (Culp's performance is a big part of it). The final monster is really a piece of NightmareFuel, and it's only a mild example. ''The Outer Limits'' must have been the scariest thing on TV at its time.
* NightmareRetardant: The Zanti Misfits from the eponymous episode, not merely for the uneven effects but the sheer fact that they're oversized ants with faces making gurgling sounds.
* SeasonalRot: The second season, while not horrible, was of very uneven quality, due in part to it being moved to a Saturday Night Timeslot against ''The Jackie Gleason Show'', which in turn caused major staffers to leave in protest, and then the production budget was cut even lower than it already was, and they tried to make the show more commercial than before. That the second season was a ratings flop and triggered its cancellation midway shows how well that turned out.
* SpecialEffectsFailure: It varies a lot. The title character of "The Galaxy Being" still looks fantastic decades later, as do many of the show's effects (Mr. Zeno's teleportation effect in "The Special One," the energy monster in "It Crawled Out of the Woodwork," and many others). But it's heartbreaking when some of the best scripts gets saddled with some of the worst effects of the series: it can be hard for a modern viewer to watch the classic "Demon With a Glass Hand" because the aliens' makeup jobs and costumes just look so pathetically cheap.
** "The Zanti Misfits" for the most part has excellent stop motion effects for the aliens, but some shots of them, most notably when they're clinging to a person or "crawling" down a wall, are obvious static puppets on strings.
** "The Man With The Power" has the scene where a rock is lifted into the air by the man's mind, where at several points you can clearly see the strings holding it up.
** The alien's makeup from "The Children of Spider County" looks fine until the character is required to talk, at which point you're reminded that it's just an immobile rubber mask.
* VisualEffectsOfAwesome: The show often achieved impressive effects for a TV show of the time, most famously the Galaxy Being from the eponymous episode.