"Spock's Brain" also had the nice rear view projector, which gave the bridge scenes more atmosphere.
"The Way to Eden" had Spock eloquently discussing Sevrin's group's rejection of technology (as well as the aforementioned point of Chekov being an actual person and not a stick figure who claimed everything was "inwented in Wenningwad by widdle owd wadies with nooclear wessels.") Seeing a guy in go-go boots pretty much makes up for the number of times only women wore the same type of outfits. I kinda dig the song as well and I still vaguely remember James Blish's adaptation for his novelization. About man finding how he had to think. (both actors had great singing voices, but I'd rather listen to them as solo performances. As a duo, they don't have the harmony of the Mamas and the Papas or ABBA... )
For all its superficial nonsense, one still can't help but to feel for the plight of the Vians in "The Empath". The novelty of the force field being tied to one's internal emotions was pretty brilliant, too.
"The Mark of Gideon" may oversimplify rather a lot, all while trying to cut costs by reusing the Enterprise sets, but a Trek episode discussing the fears of overpopulation is still laudable. Indeed, a lot of season 3 is surprisingly poor despite utilizing some highly compelling societal concepts. A lot of that is due to budget, which "Gideon" epitomizes and most directly personifies. That and the actor playing Quinteros in TNG's classic episode "11001001" (it's one of my all-time favorite gems, season 1 or otherwise) is in this TOS episode too.
"The Lights of Zetar" also contrives a lot, especially for the galactic library having no defenses, but they really sold the episode with the horror element, working better than even some horror movies of the era. (
Rosemary's Baby notwithstanding...)
"The Omega Glory" is actually a very strong entry into the show until the impossibility of the American flag and US Constitution showing up. That and anything Morgan Woodward is in is instantly elevated by his presence.
"The Deadly Years" has some top notch performances from everyone affected by the aging radiation.
"Patterns of Force", capitalizing on the then-trend of saving budget by incorporating the horrors of Naziism, still had a lot of yummy eye candy... and, of course, Skip Homier who clearly enjoyed doing villain roles on Star Rrek.
"Bread and Circuses" has a lot of wishful thinking at times, but despite its trappings it remained surprisingly engaging to watch, has the actor who played Mr. Atoz as another good guy (Septimus) epitomizing the core optimism of
Star Trek, and one heck of an ending as the crew are beamed up at Merik's behest just before being shot to death by Claudius' machine gun-wielding guards and, of course, Merik being stabbed by Claudius. Kirk signaling to Scotty that they're in trouble but nobody is to mount a rescue was a nice twist. And Uhura getting to figure out "the Sun Worshippers" was pretty cool, too - and, again, and for the late 1960s, was trying to show hope to a
mainstream audience.
"Turnabout Intruder" has a decent premise and robust acting, despite it being well known by the cast and crew the show would not be renewed.
"Catspaw" as Kirk admitting they can synthesize "precious" gems so they don't care. As a kid, seeing the Enterprise in 2" form on a chain looked cool, unlike Chekov and his Monkees wig, which is the one thing he never admitted that
was made in Leningrad by a little old lady after she got bored inventing Scotch and drunk from taste-testing all those whiskey recipes under her development...
"I, Mudd" is the epitome of self-conscious nonsense done right. "I, Mudd" had some hysterical moments in what amounts to yet another "Kirk nags a computer to death" episode, which also happens to incorporate as much pervy grotesqueness that TOS might dare to do without turning on the censors (so to speak). The twins reciting their lines added just enough camp to make everything work along with the regular cast. I prefer by far "Mudd's Women", but "I, Mudd" uses self-consciousness in a surprisingly effective way. That and Spock gets to recite some fun illogical to immobilize the two androids Chekov wanted to get it on with...) That and I think Kirk was potentially but mildly jealous of Norman, for not conceptually dissimilar reasons to why Chekov wanted the Alices (as they were more fun than Leningrad, even spoken in the actual episode...) as they all seemed to have been, um, well-built... oh, the crushes I had as a teen... but that's 1967, not 1987...
"The Changeling" is often cringe inducing and convenient-beyond-magic with its more "dramatic" scenes, but I still like the
concept of two AI satellites colliding, somehow repairing itself due to its AI, and reprogramming itself to cause harm instead of good... and all by one big accidental happenstance. Just don't ask how it made such powerful weaponry or how Kirk repeated the same limited number of gaffes NOMAD had despite NOMAD engaging in a lot more of them, but thankfully NOMAD was so imperfect it didn't figure that out because if it had it would have conveniently self-destructed even sooner. But something like a third of all TOS episodes all revolve around "Kirk is good, computer is evil." Complete with introducing loooooooove to the convenient female guest of the week, which "Changeling" oddly lacks? Why do I now want to go waddle off and sit through "Zardoz"? Especially when Kirk, if landing on that planet, wouldn't live too long because all his ex-flings called up the locals in advance to talk about what
wasn't good, uh-oh...
Okay, and Spock instructing Bones on how to put on his boot is cute.
I love how you can always be counted on to rag on Plato, JB! 
