The Original Series

Star Trek (1966-1969), also known as The Original Series (TOS) is where everything began and it has plenty of comfy episodes. Despite originally airing in the 60s, it generally holds up pretty well. It establishes a formula the rest of the franchise will follow and many of the episodes are genuinely amazing. Much and more has been said about its allegories for real-world issues, and much of it is still (sadly) relevant today. If you can look past occasionally poorly-aged 1960sisms, you will be treated to an extremely progressive, transgressive, and (oftentimes) silly gem of a science fiction program. This show lives and dies by the interplay between its core three characters: Kirk, Spock, and McCoy.

Captain Kirk

James T Kirk (William Shatner) is the captain of the USS Enterprise and the face of the show. He's tactical and cunning and diplomatic and everything a good captain should be. His crew respects him and follows his orders unquestionably. He's an adventure hero who is good at his job. At the same time, he... fucks. Like, anyone he can. Sexually or otherwise. There is a devil-may-care, "I do what I want" panache about him that you'll either love or hate. And I'm all here for it.

Mr Spock

Spock (Leonard Nimoy) is half-human and half-Vulcan and is the ship's science officer and second-in-command. He is intelligent, logical, and stoic. Part of Vulcan philosophy is suppressing one's emotions and relying on cold logic. Spock is often caught in an internal tug-of-war between his two halves. He provides logical reasoning for every situation and is a foil to the passion-fueled Dr McCoy.

Dr McCoy

Leonard "Bones" McCoy (DeForest Kelley) is the ship's Chief Medical Officer. He's a grumpy, cantankerous doctor who distrusts technology and loves his friends. If Spock is the voice of logical reason, Dr McCoy is the voice of passion and morality. Despite their constant bickering, McCoy has a deep respect for Spock and all his fellow crewmates. He's Kirk's confidant and counselor and always doses his advice with good humor.

"The Naked Time" - S1 E4

A virus gets on the ship that makes everyone drunk. We get to see what each character looks like when their inhibitions are lowered, which (like Amok Time), is a great character study on Spock.

"Amok Time" - S2 E1

Spock goes into heat in this episode (did I mention this show is sexual?) and needs to go back to Vulcan to relieve himself. It's a great reversal for the normally reserved Spock and has some great interactions between him and Kirk.

"The Trouble with Tribbles" - S2 E15

This is a bit of a silly episode. While dealing with a Klingon plot on a space station, a bunch of little fluffball guys start getting everywhere. There is some tension, but for the most part everyone is just having a bit of a sci-fi romp.

BONUS!

DS9 pays tribute to "The Trouble with Tribbles" by travelling "back in time" to this episode. Check out "Trials and Tribble-ations" - S5 E6!