Star Trek: Enterprise
During the Xindi arc that was in fact the entire third season of Enterprise, Star Trek finally got to do zombies. Let me rephrase that for maximum awesome: Vulcan zombies.
Enterprise, as you may or may not know, was a "prequel," in that it was set before the events of any other Star Trek. As such, there were a lot of expectations, and quite gleefully Enterprise more or less subverted all of them. The biggest subversion concerned Vulcans. Vulcans in Enterprise hated humans, and they made no bones about it. Remember Star Trek: First Contact and that feel-good moment at the end when it turns out the title refers to Vulcans? And Enterprise was more or less a sequel to First Contact, mind you (there was even a whole episode dedicated to what happened to all the Borg remains, "Regeneration"). That whole idea turned out a lot worse in practice than in theory, as it turns out, Vulcans interacting with humans.
And while Vulcans were still more or less completely recognizable, as a culture they exhibited a distinct break from how Spock would later represent them. The biggest break was in fact how the idea of mind-melds were treated at this time. "Stigma" famously presented Vulcans who practiced them as more or less analogous to the LGBT community. Fans were pretty livid about Vulcans in Enterprise. By the fourth season, Captain Archer helps revive the philosophy of the famous Surak, founder of Vulcan logic, as the fourth season made continuous efforts to appease fans. But of course, the fourth season was also the last one of the series. (Too little too late.)
So what do Vulcan zombies have to do with any of this? In short, T'Pol's arc in the third season, which itself was a manifestation of the inner turmoil she'd experienced all along, the lone Vulcan in a ship crewed almost exclusively by humans (aside from the dear Dr. Phlox, naturally). Some fans remember T'Pol best for the sexy times she spent in various states of undress (a significant moment of which occurred in the third season), but she was in fact a notably nuanced character whose journey in the series closely matched that of Trip, arguably the best thing about the whole series and with whom she shared most of her screen time.
Zombie Vulcans is what would have happened to T'Pol, too, if she hadn't known what to do that season, even if there were a few stumbling blocks along the way. The region of space where the five species of Xindi inhabited was bad for Vulcans, so bad that if entered without precautions taken, they became zombie Vulcans. "Impulse" is full of zombie Vulcans. That's the whole episode.
And Spock was at the receiving end of human bigotry, it must be remembered. How do you think that happens, anyway? Because the road to what has always been described as the perfect future was in fact a bumpy one. Along the way, zombie Vulcans. Because there ought to be some fun involved, right?