That was “The Way to Eden,” originally titled “Joanna.” McCoy’s daughter became Chekov’s Russian girlfriend. The first drafts were written by Dorothy Fontana, who eventually quit in disgust over the way things were going.
Well, seeing that Hell is usually described as ugly, you aren’t far off. 
Aw, c’mon. We get to see Kirk, Spock and McCoy as codgers in “The Deadly Years”! And there’s a nice scene with a senile Kirk railing against Spock, who’s all wounded dignity, for betraying him. Not a great ST ep, but not bad, either.
Kids, don’t try this at home! (I’ll have to look for that episode.)
That episode was written by Robert Bloch, so it cannot possibly be the worst of anything. Though it was not as good as Wolf in the Fold, also written by him and of the “Yours Truly, Jack the Ripper” series.
Are you kidding? I tried it as soon as I could get my hands on a box of saltpeter.
Are you calling “Amok Time” the worst episode? It’s generally considered to be one of the best. It gave us a lot of background about Vulcan. It introduced the Ponn Farr and many other aspects of Vulcan culture. It established Spock as belonging to the same family as the esteemed Vulcan leader, T’Pau.
They looked more like bundles of asparagus.
Maybe they were digitized into cuthulu. 
I thought they looked like some kind of scrawny chicken monsters.
I never really liked Turnabout Intruder, except for Shatner as a chick*
*I can always find something to redeem even the worst ep.
I liked Lazarus, David Soul, Space Hippies, planet of dumb chicks, space ghost, and Baby Q, among others
Sylvia and Korob in their natural state.
I guess I was focused on their heads, which is kinda squidish.
As a kid, I thought they were incredibly creepy!
Tiny little monsters…
They ARE creepy or as Spock says, “A life form totally alien to our galaxy.”
I half expected Gilligan’s Island end of scene music when I first saw them.
I still think they look as though they were assembled from a Kroger dumpster.
Paradise Syndrome is pretty bad. The plot was actually a good idea. Alien deflector that destroys asteroids.
But why make the people there Indians. We get silly shots of Kirk in a headband and buckskins. Looked like costumes from Daniel Boone.
But without it we never would have had one of the best lines in Galaxy Quest,
[QUOTE=Guy Fleegman]
Look around you – can you construct some sort of rudimentary lathe?
[/QUOTE]
And as the Mission Log guys note, there are 430 people on the Enterprise. Why does everyone have to go deflect the asteroid? Why not leave a detachment to search for the captain?
Sheesh, have you ever considered reading the thread?
But really, the best line is when Gwen deMarco sees the chompers and shouts “Screw that”, except you can see she actually said something else – and I always wondered if the filmmaker did that on purpose or had to clean it up for a lower rating.
Star Trek in all its incarnations is riddled with plot holes, formulaic absurds and straight-up scientific errors. One of my favorites is from Court Martial, where Kirk says, “When I flip this switch, all the sounds in the ship will be amplified by a factor of one to the fourth power.” The quality of the writing and plotting improved incrementally over the decades, to the point that Enterprise actually started to get interesting. It had a much more believable feel than its later predecessors.