^ Ditto on "A Taste of Armageddon"; a seriously underrated TOS outing. I enjoyed the conflicts between Fox and Scott, Kirk and Anan 7, and even got a chuckle out of the brief confrontation between the regal-but-suicidal Mea 3 and Yeoman Tamura. "Taste" was one of those first-year stories that showed that while the Federation has high principles and they want to "try to take it easy", if you mess with them, they take care of business.
I also feel the same way about "Dagger of the Mind". My mother used to work in the dietary department of a local state mental hospital. She knows many of the patients there are not capable of caring for themselves, yet the de-institutionalization of the last 50+ years is putting more and more of those patients out on the street. "Dagger" seemed to speak to me about man's inhumanity to man, about how our generation is mistreating some of our weakest, most marginalized citizens. By showing Kirk being subjected to the Neural Neutralizer, it was like a microcosm of what was wrong at Tantalus, which itself was a statement on how we neglect or abuse the mentally ill. And the image of Noel kicking the agressor-security goon back into the electric substation to be burned to death was powerful; like she became a proxy for the infirmed patients of "Devil's Island", defending herself to stop their criminal enterprise. And I always loved the way Spock took charge and started ripping the place apart and even the redshirts were cornering the henchmen at gunpoint. (I'm looking forward to STAR TREK: NEW VOYAGES/PHASE II's adaptation of the 1970's prose short-story "Mind Sifter" with great anticipation, BTW.)
I think all of TOS' second year is seriously underrated. Some people trash it because it used levity, but I thoroughly enjoyed it. "Metamorphosis" was one of the best stories of TOS, and I'm shocked at how underrated it is; the story goes directly to what TOS intro-monologue said it was all about. "Bread and Circuses" is my all-time favorite TOS story. Again, Kirk and company must deal with hostile aliens, but even while at gunpoint they keep it cool and do not overreact. Kirk even commends Scotty for the harmless EMP blackout. The story's cleverly layered religious message resonates with me to this day. "Obsession" remains outstanding as the best "the captain has issues" stories of any of the STAR TREK series. The story, the acting and the "creature" concept still blow me away! And "The Ultimate Computer" is still relevant in its subject matter, over 45 years after it first aired.
Of all the "Kirk's girlfriend comes calling" stories, "Elaan of Troyius" is the best. At least there's a sci fi plot mixed in with the captain's dalliance this time. And yes, I enjoyed the disarm-the-bomb/restore-the-engines/deal-with-the-Klingons subplot as well. Not as richly layered and dramatic as the excellent "A Private Little War", but still an outstanding Cold Warrior's story.
"Is There in Truth No Beauty?" is a romantic tale on many levels that seems to get recognized by the fans, but only sparingly. This never fails to amaze and disappoint me. Both "Is There in Truth No Beauty?" and "The Tholian Web" deal with the very sci fi notion that deep space is a place far removed from humanity's conventional three-dimensional thinking, forcing the Enterprise crew to "think outside the box" in order to survive. Fans seem to want to concentrate on some "transwarp" angle, or casting the Tholians as scheming villains, but that wasn't what those stories were about. They were about confronting the unknown (both within and the Great Beyond) and having to use their intellect to cope in a place far removed from their previous experience.
"That Which Survives", "Let That Be Your Last Battlefield", "The Lights of Zetar" and "Requiem for Methuselah" all had romanticized themes that seemed the characterize TOS' third year. They also exhibited the show's growing range of subject matter and story types. Despite obvious lapses in production values in these shows, they still seem underrated.