12. The Menagerie: This is a two-parter, and we get to see the original pilot in flashbacks.
11. See above.
10. The Tholian Web: Spock takes command of the enterprise when Captain Kirk goes missing.
9. The Naked Time: When a strange virus causes the crew to lose control of their emotions Spock has a break down. Brilliantly acted by Nimoy.
8. All our Yesterdays: A time travel story. Spock exhibits what Vulcans were like before they learned to control their emotions.
7. The Immunity Syndrome: When a starship crewed by Vulcans is destroyed Spock has to learn what caused them to die.
6. Is There in Truth No Beauty: The Enterprise crew meets an alien ambassador named Kollos who is so ugly that his face causes humans to go mad.
5. Balance of Terror: The first appearance of the Romulans. Spock is calm and dignified in the face of racism and paranoia.
4. City on the Edge of Forever: Arguably the best Star Trek episode, Kirk, Spock and McCoy meet a woman whose life and death could change history. ‘He knows Doctor. He knows…’
3. Mirror, Mirror: An alternate universe story with Spock sporting a goatee. A classic episode.
2. Journey to Babel: En route to crucial peace talks, The Enterprise plays host to Spock’s parents.
1. Amok Time: See my essay below!
Hugo Award-winning author Theodore Sturgeon wrote this second season episode, and it introduced viewers to Spock’s homeworld, Vulcan. I love the episode because it is so inventive, and it shed light on my favourite Star Trek character. “Amok Time” featured the Vulcan mating ritual ‘pon farr’, the first use of the Vulcan salute, and the enduring phrase “Live long and prosper.”
The show treated Vulcan culture and traditions with respect, and after Spock and Captain Kirk fight to the death (and how awesome is that!), the famed Vulcan logic is represented by Spock’s bride, T’Pring, who explains in cold and calculating tones why she did not want to be his bride, and her plan to break her relationship with him.
Before beaming up, Spock delivers a great line: "After a time, you may find that having is not so pleasing a thing after all as wanting. It is not logical, but it is often true."