Star Trek: 10 Greatest Genre Episodes Ever

This genre is one of the most straightforward ones on this list. According to Britannica.com, comedy is a:

Type of drama or other art form the chief object of which, according to modern notions, is to amuse.

The Original Series took itself quite seriously, despite adding in the occasional jokes (often at Spock's expense) for some of the early episodes. It was still establishing what Star Trek was, so dipping into the comedy pool too early could have thrown the writers for a loop. By the time that The Trouble With Tribbles aired, Star Trek knew exactly what it was - and the episode shines because of it.

The Klingons had been established. Kirk and Spock's relationship had been established. Audiences knew what to expect when a rogue trader came into town. Starbases were often spots of bureaucracy and tedium. Mix all of these, and one gets the perfect outcome: a funny episode that elicits laughs almost sixty years later.

Almost all of the principal cast appear (George Takei was unavailable as he was filming the Green Berets) and they all get farcical parts to play. Uhura and Chekov introduce the Tribbles to the Enterprise, McCoy analyses them, Spock fawns on them, and Scotty gets into a fistfight with a Klingon. William Shatner shines as the put-upon captain who would rather do anything else than deal with the squabbling of directors and delegates, though maybe not if it meant standing under more of those storage units.

The episode works so well that it was revisited in tribute to the franchise's thirtieth birthday. The comedy is so well done that the joke works twice, and Trials And Tribble-ations is just as much fun to enjoy.