My own...admittedly subjective...feelings on TOS Season 3, which I consider the worst of Trek:
Genuinely Good: Day of the Dove (Kang!), and All Our Yesterdays (one of the better TOS time travel episodes).
Okay: The Enterprise Incident, Is There No Truth In Beauty?, The Tholian Web, That Which Survives, Who Gods Destroy. These are all fine episodes, even though they have some flaws.
Bad: Everything else.
I should state I consider a bad episode of Trek to be anything I rate a 3 or lower. Some bad episodes do have redeeming qualities. Like, I think Spock's Brain is so dopey that it's stupid fun. The problem is a lot of episodes (The Paradise Syndrome, The Cloud Minders, The Lights of Zetar) are both bad and boring.
I won't use numbered ratings, since how everyone defines those ratings can vary, but here's my take...
TOS Season 3
"Spock's Brain" --> Guilty Pleasure. I know it's bad, but I don't care!
"The Enterprise Incident" --> Excellent. This is in my Top 10 of TOS.
"The Paradise Syndrome" --> Okay
"And the Children Shall Lead" --> Terrible
"Is There In Truth No Beauty" --> Mediocre Story,
Trippy Visuals!
"Spectre of the Gun" --> Okay
"Day of the Dove" --> Great
"For the World Is Hollow and I Have Touched the Sky" --> Good
"The Tholian Web" --> Great
"Plato's Stepchildren" --> Dead Neutral. I understand what they were going for, but that doesn't mean I enjoy it.
"Wink of an Eye" --> Okay
"The Empath" --> Excellent. This seems to be a "love it" or "hate it" episode.
"Elaan of Troyious" --> Mixed Opinion.
"Whom Gods Destroy" --> Middling. It's true saving grace is that it gave me my Username.
"Let That Be Your Last Battlefield" --> Bad, for a whole host of reasons: including False Equivalency.
"The Mark of Gideon" --> Mediocre. I wanted to like this more than I did.
"That Which Survives" --> Okay, but also one I just happen to like regardless.
"The Lights of Zetar" --> Ehhh...
"Requiem for Methuselah" --> I have a mixed opinion of this one.
"The Way to Eden" --> Guilty Pleasure. Just like "Spock's Brain".
"The Cloud Minders" --> Good
"The Savage Curtain" --> Ehhh... It has my favorite President... it introduces Surak...
and that's about it!
"All Our Yesterdays" --> Good, but let's be real: It's the Spock/McCoy/Zarabeth storyline that's
really carrying it!
"Turnabout Intruder" --> Mixed Opinion. If I pretend Lester-Kirk is Trump, I get a big kick out of it.
Overall:
"Good" or Better --> 7 episodes
"Okay" --> 4
"Mediocre" --> 7
"Poor" --> 2
"Bad" or Worse --> 2
"So Bad, It's Good!" --> 2
Consolidated Version:
Okay/Good/Better --> 11
Mediocre --> 7
Poor/Bad/Worse --> 6
Coming up next (whenever I feel like it): TNG Season 1 and
maybe TNG Season 7.