A good friend of mine (in real life and on Facebook) made an interesting and provocative assertion, namely, that every incarnation of "Star Trek" has been worse than the previous series. I responded that I didn't think the original series (TOS) could be compared to the others, because its production values, tone, and acting were so different; and that I agreed with the assertion as to the offspring except that I believed that "Deep Space Nine" (DS9) was superior to its predecessor. Naturally, this being Facebook, a time-sucking argument ensued.
I didn't want to attack TOS, but when push came to shove, I resorted to pointing out all the dreck from the third season - episodes like
Spock's Brain,
The Mark of Gideon, and
The Cloud Miners, among others. My friend defended even these atrocities, noting that they were memorable. Apart from the general awfulness, I remembered not very much about Spock's Brain - and it turned out that the line that I thought I remembered wasn't even in
the shooting script! That episode was so bad, I was inventing better dialogue for it....
Anyway, my friend then asserted that the best episodes of TOS were better than the best episodes of the other series. "Best" is going to be subjective, of course, but I decided to come up with my list of the five best episodes from each of the series.