“THE SQUIRE OF GOTHOS"
The titular Squire (Trelane) is TOS's version of Q, and Spock is not in the mood for his games. Trelane is an all-powerful nuisance and his tricks don't even merit a "fascinating" from Spock. He lets this trickster bully know exactly what he thinks of him in this episode's best moment, verbally laying this dude flat. If Nimoy deploys every bit of gravitas necessary to deliver the line, and it almost (almost) calls for an ironic Vulcan salute at the end.
As he says: “I object to you. I object to intellect without discipline. I object to power without constructive purpose.” This is a human objection, it is a Vulcan objection, and it is also Spock fearlessly speaking truth to power. He's had enough of watching the crew get toyed with, and uses every argument in his arsenal. He is succinct, brilliant, and perfectly on target.
“THE DOOMSDAY MACHINE"
Another moment of Spock standing up to power comes in “The Doomsday Machine” where he ceases to tolerate the awful leadership of Commodore Decker. Not content to lose one ship, Decker is ready to sacrifice the Enterprise (and Captain Kirk) to fight his own space age Moby Dick. Logic would dictate that Spock adhere to the chain of command, but the needs of the many… you know.
Spock relieves this jerk from command and takes the Enterprise back just in time. Everyone watching takes a grateful breath. “You may file a formal complaint with Starfleet Command, assuming we survive to reach a starbase. But you are relieved,” he says.
The hell with command structure. Decker may have outranked Spock, but he was unfit for service. In a way, it was more logical for Spock to intervene here (in the face of death), but in the moment Nimoy once again makes you feel that he’s speaking out of logic, duty, and friendship all at once. As a bonus, he’s reading this lunatic the riot act and we love to see it.
“THE ENEMY WITHIN"
This is the classic Original Series episode where Kirk gets split in two, thanks to a transporter accident. There's meek Kirk, and violent Kirk. Spock and his perennial foil, Dr. McCoy (DeForest Kelley), have to figure out what to do.
In one particular scene, Spock and McCoy argue about the situation right in front of one of the suffering Kirks. Spock is rarely better than he is when he's mid-argument with McCoy, as Kelley and Nimoy brought out the best in each other. As much as McCoy wouldn't want to admit it, Spock and McCoy brought out the best in each other too.
Spock talks about his dual nature here in a very real way. Being split in two is not just a theory, as McCoy suggests. "Being split in two halves is no theory with me, Doctor," Spock says. "I have a human half, you see, as well as an alien half submerged, constantly at war with each other. Personal experience, Doctor. I survive it because my intelligence wins out over both, makes them live together."
He had yet to lay it all out as bluntly as that, and the true power of Spock's character is revealed in the moment. He is a being constantly at war with himself but is able to control it. That he can be the incredible officer, friend, and person that he is while dealing with that is nothing short of miraculous. It's not something that Spock brings up very often, but here, Nimoy peels back the curtain on Spock's struggle and the pain that comes with it. The result speaks for itself.
“BALANCE OF TERROR"
The secretive enemies of Starfleet, the Romulans, are seen at long last. They look just like Vulcans, and not even Spock was aware of this. The unfortunate bridge officer, Mr. Styles, wastes no time engaging in a non-stop parade of bigotry for the entire episode.
Spock never buckles under the a**holery of Styles. In one great moment (in an all-time classic episode full of them), Spock advises everyone what he thinks they should do about their standoff with a Romulan ship. Styles is already convinced Spock is a traitor, and may assume that he's gonna talk about diplomacy or some other half measure. Spock doesn't advise that at all.
Spock suggests they attack. If the Romulans are the distant (and violent) relations of the Vulcans, then they are in trouble and attacking is the only course of action. Going on the offensive is not something Spock usually suggests, and especially in this moment it smacks you right in the face. His reasons for doing so should make anyone who is doubting his loyalty shut their mouths, but bigots are bigots, and Styles doesn't like to keep his bigotry in his quarters. Thankfully, Spock is above such petty things. Attack.
“AMOK TIME"
Are we allowed to say that the moment here is the entire episode?
We love to see Spock bicker with McCoy in our all-time favorite Spock episode, but we also love his friendship with Captain Kirk. Though Spock has also said (in a previous episode and moment on this list) that he is able to keep the two sides of him in check, he doesn't manage that in this classic entry, thanks to the Vulcan condition known as Pon farr. Pon farr more or less means that the Vulcan experiencing it has to get it on, and get it on fast.
The Enterprise heads to Vulcan to see what is going on after Spock starts flipping out, and part of his newfound angst includes throwing a full bowl of soup at a wall. Poor Nurse Chapel only wanted to help, but Spock tosses her out with the soup. Yes, the soup hitting the wall counts as a moment.
Once Spock and company arrive on Vulcan, they must undergo Vulcan rituals which end with Spock having to fight Kirk to the death. His captain, his best friend, his everything; he has to kill him. He thinks that he has done this as he beams back to the Enterprise.
Kirk was never alone, though, so of course he's not dead. It was a ruse, and the moment comes when the despondent Spock sees that Kirk is still alive. He grabs him, and gives a full smile. This is something that Vulcans never do, and it is something very rare even for the half-human Spock. The riveting episode is full of Spock grappling (both literally and figuratively) with his suppressed Vulcan emotions, but it ends with Spock's human side winning out. Human, Vulcan, it doesn't matter here. The only thing that matters is that his best friend isn't dead. He's happy about that.
There are so many more moments that we could add, because there's at least one brilliant Spock moment in every episode. That's the power of the character. He is the very soul of the franchise, and to use his own phrase, he is endlessly fascinating.