Okay, I actually don't think "Code of Honor" is as bad as so many have said. It's not TNG's best, but not their worst either.
1. Seriously, the casting choices for the Ligonians is the only problem. Had they gone with anyone else, like Japanese since there's shades of feudal Japan in there, I don't think it would have gotten the flak it gets.
Agreed, it's weird how the same plot would be seen differently otherwise.
Picard lobbing torpedoes is clearly a violation of the prime directive and something so dumb even "cowboy diplomats" like Kirk would be appalled. The next time we see anything like this (and not because the captain is taken over by some incorporeal glowing light bulb critters) is in DS9's "For the Uniform" except they made it work.
But "Justice" has all the guest cast being blue-eyed blondes, even with wigs if needed. Isn't that the same problem as CoH? (Jessie Lawrence Ferguson and Patrick Stewart both rise above the script's often pitiful dialogue, though the same can't be said for "Justice" - a script which is genuinely worse and mangles anything about the prime directive even worse... ...and the security chief is the character handled the worst and solely for the sake of compelling everyone beaming down to "the oily snu-snu planet of death if you fart on a fenced flower for it cannot flee!" at the drop of a hat. )
2. As you pointed out Unimatrix Q, it's the only real original timeline Tasha episode. (She did get some good scenes throughout the season, though.)
And some bad scenes too. Tasha was more than just set dressing, especially as her background told to the audience had arguably the most potential.
3. We get a good glimpse at Data and Geordi's friendship here. This is the first time we see them as pals, as the friendship grows into them being best friends. I have a soft spot for Data, as it's likely been apparent over the years, so scenes that feature him always get a thumbs up from me.
TNG's best duo by far, IMHO. Originally intended to be "the perceivers", it didn't quite work out that way but they're still a robust duo.
4. Troi got some good use, and it was in her actual job. Both when she was using some psychology to get Yar to be aware of her ego to help be objective, and while advising Picard in his diplomatic relations. Her character got the shaft a lot in later years, but this was not one of those times, and it's a good reminder of why she actually deserves to sit in the center area of the Bridge.
^^this
Good challenges. Both episodes are tough to defend. But...
"SPOCK'S BRAIN"
1. This episode utilizes the entire main cast well. (Not during a lot of the episode, but they definitely got more to do in the episode than normal.) When Kirk is trying to decide which planet to go to, each give logical, valid reasons for their choices given their areas of expertise. Uhura, I feel, gives the best observation when she asks why Spock's brain... which I think was the unconscious reason why Kirk picked the right planet. I love watching episodes where the entire crew gets utilized well.
2. Spock's brain was stolen... that is a horror concept. I love horror, and while the execution is not as good as the idea, it was enough for me to love the horror aspect of having such a vital piece of yourself removed. Particularly as a kid when I first saw this. TOS didn't dip into horror often, but when it did, I remembered it well.
3. For much of the episode, our heroes did not have Spock and his vast knowledge and problem solving skills to resolve things. This was a very rare case, and it was great to watch them do things with the proverbial one hand tied behind their backs.
1. 100% true. Also, the use of backlit projector added to more authenticity on the bridge as well as some new camera angles. It is fresher. The right planet as guessed by Kirk, in being a devolved civilization, was something of a fad in dystopian fiction of the era so that would be a fresher take on the show as well... a shame the episode was written as a dare because the writer felt the actors and makers took the show too seriously (sigh...)
2. And only Spock would opine without any emotion how fascinating it is to be a glorified HVAC and plumbing control unit.

(A stupid concept not just because machinery is more reliable and consistent (though a microchip lasting 10,000 years is questionable) and how organic matter just doesn't live that long but a lot of sci-fi even after 1969 tarted up "ten thousand years" or even far longer as a means to get the audience psyched (note, it rarely worked, and Doctor Who's "Four to Doomsday" was an early example in actually asking how organic matter can endure for all that time...)
3. A very nice twist. The ending is still way too rushed and while no explanation would have worked even remotely neatly, having McCoy try "the teacher" again might have been preferable to the vocal chord enabling (oh jeez...) The teacher's AI just wasn't going to let Kara or anyone else put back the brainz as it was teaching all its subjects what it needed.
3.
"TURNABOUT INTRUDER"
1. I've noticed people tend to watch movies and shows from decades ago and judge them by the standards of today, or at least the 21st century. I think it not only detracts from enjoying the product, but is being unfair to it, as well. Look at the time STAR TREK was produced. Few shows or movies were as inclusive with their cast. How many had a black woman in charge of a highly important department? (I mean this seriously... communications is an incredibly important department. I'm certain many, if not all, current and former military reading or posting here would agree.) Or have a Japanese AND a Russian officer working side by side with Americans? Except for South America, EVERY habitable continent is represented in the senior staff. This, more than any other reason, is why I think this episode gets so much hate... because it's viewed as misogynistic. And viewing from that lens, I can agree on that point. But I feel that is wrong and unfair. Make Janice Lester a man, and it could easily be a rival from Kirk's Academy days or early career trying the exact same thing. (Hell, we have seen that before with "COURT MARTIAL".) I bet the general opinion would be very different.
2. Speaking of Lester, I actually thought it was a smart idea to have the villain be a former love interest of Kirk. And frankly, if she kept a cooler head, her plan could have actually succeeded. How many people would have gotten as far as they did against Kirk? Damned few. In this way, it could be argued this episode was not misogynistic because the woman villain nearly outwitted our heroes. That rarely, if ever, happened during that era.
3. Watching William Shatner descend further and further into madness as Lester is honestly a treat. He did an excellent job. This was a good showcase of Shatner's abilities. I must also give a lot of credit to Sandra Smith, who I felt captured the essence of Kirk in her performance. I really enjoyed watching the two in scenes together.
4. This is more of an unconscious thing, but this episode had a nice full circle callback to its very first aired episode, "THE MAN TRAP". Both dealt with an archaeological expedition.
1. Agreed. The times in which it were made can add a lot... That said, Chekov was the butt of backhanded jokes in all of season 2 and referred to indirectly for one story in season 3 with "If I wanted a Russian history lesson I'd have brought down Chekov" as Chekov himself was retooled to no longer be the punch line (Freiberger's era isn't a total flop...)
2. Good point!
3. Shatner and Smith both steal the show as their respective roles needed.
4. Great observation with bookends (albeit a probably unintentional one from the makers.)