The original script yes, Corbomite's one of my top ten, maybe top five TOS eps.
My only real criticism is that it's one of the first in a long line of episodes wherein the Enterprise discovers a monstrously powerful force on the borders of Federation space, which we'll never hear from, ever again. -_- See also: Excalbians, Metrons, Organians, Gothosians (or whatever), space amoebae.
Let's hope they were not literally never heard from again--for then, what happened to poor Bailey?
Of those you mentioned, the First Federation appears to be the only one that is known to actually venture out into space on any kind of significant scale, placing their buoys (well, they were mobile, but you know what I mean) and so forth.
The Excalbians appear to have had strange dealings with visitors often enough for there to be "old space legends" about their planet, but they are so alien and appeared to encounter a very wide conceptual gulf in their communications with Kirk and company. I can see the Federation is not likely to visit there again (!), and there's no indication they like to leave their planet, especially as they appear quite comfortable with the manipulation of visitors in pursuit of "the need to know new things."
The Metrons specified they didn't want contact for a long time, and appeared able to conceal their presence from the intruders as well, so with this added to the fact that they appeared to reside in the disputed Gorn border area, it is easy to imagine that there's been no, or minimal, follow-up contact.
The Organians certainly were not burdened by any homegrown version of the Prime Directive and imposed their will on the Federation and Klingons, but also mentioned that the presence of beings like Our Heroes was painful to them. It certainly appears that they desired no further contact. I am willing to bet that the terms to which the Organians subjected both sides lasted for a while and then stopped, after which there was either no Organia there when they went to ask about it, or an area into which they were denied entry.
Gothosians I will take to mean Trelane and his "parents" and such, and considering the fact that the planet was not only likely a construct but also mobile, I don't know if they were necessarily "from" that area or spent a lot of time there. It is believable that they were not encountered again, though they may well have been...anywhere.
As for the "space amoebae" creatures, I do think it was unlikely that there was only one (since they divide), but I am not sure how fast they move. Encounters with them might be rare even if there were a bunch. There was some question that they might be extragalactic in origin. I think Starfleet is able to deal with them now, so even if others were encountered, those were tales of other ships and crews.
It does seem that Federation space might border or encompass a number of planets that don't want contact with outsiders, and some of these appear to be older and more advanced civilizations that either treat the visitors as playthings or zoo exhibits, or are simply waiting for them to attain a higher level of development before what they can proceed with what they consider more meaningful contact. This is part of TOS I liked: the idea that there were some
really alien creatures out there and some of them had been around for a
really long time, and all the business of warping around and colonizing planets and stuff just seemed totally unimportant to them for one reason or another. TAS had some of this, too. I guess the First Federation was playing this role a little bit, but only as a test.
It is especially interesting to me to think of civilizations like that with which the Federation DID achieve some sort of meaningful contact. The Melkot may qualify. They had strange but advanced tech with which they could have explored space (and may have in the past), but used it to guard their borders as they retreated into isolation. They played with the somewhat-inferior minds of their Federation guests and exposed them to danger, but ultimately decided they were OK after all and appeared to want real diplomatic contact. I have always wondered what it would be like for the Federation to have some "senior partners" like the Melkots or perhaps Antosians, who are ostensibly Federated planets but probably limit their participation to occasional voting and cultural exchange (in the Antosian example, I tend to doubt they would have shared all their knowledge). Or would the refusal to share all knowledge prohibit membership and restrict such a civilization to some sort of associate status?
Hey, the Medusans are extremely alien in form but they appeared to make a real effort to participate fully.
Well, I seem to have gone on a bit, but no harm done. I'm on a TOS kick lately, is the thing.
