20. Amok Time

Even Vulcans need to get some, right? The episode that featured the debut of planet Vulcan features Spock in a rather nasty bout of heat that will kill him in about a week unless he is taken immediately to his home planet to mate. Also featured in this episode is one of the most famous fight scenes of the series, one that will be rather hilariously parodied in Jim Carreys The Cable Guy some thirty years later. Captain Kirk is chosen as challenger in a battle to the death for the affection of Spocks wife, TPring. When Dr. McCoy injects Kirk with a neuroparalyzer disguised as an oxygen compound, it simulates Kirks death so that Spock would emerge victorious. Once back aboard the Enterprise, Spock announces his intention to resign his commission due to his actions but then shows an overwhelming amount of *gulp* emotion when he finds Kirk alive and well.
19. The Corbomite Maneuver
Indeed, one of the best episodes of all time also has one of the most confusing endings of all time. An unmanned probe destroyed by the Enterprise leads Balok, captain of the First Federation ship Fesarius right to them. Balok is probably one of the most butt ugly aliens to ever hit the tubes, and he also doesnt exist, but more on that later. Balok determines that the Enterprise is too dangerous to leave alone and must be destroyed; however, in a fit of mercy, he grants ten minutes of spiritual meditation for the crew before death. The Captain pulls one of the most badass bluffs of all time, warning the Fesarius that an imaginary substance known as corbomite would ricochet attacks of any kind against the Enterprise, thus destroying the Fesarius by their own hands. The bluff worked, apparently, and Kirk and a landing party beam aboard a shuttle left behind by the enemy vessel, only to find that Balok was a really creepy talking baby that gives the talking baby from those Super Bowl commercials a run for his money. But I guess you have to have a façade that horrifying to intimidate your enemies when you look like Balok.