Real World article
(written from a Production point of view)
TOS Viewers Choice 1

William Shatner introduces "The Trouble with Tribbles"

The Star Trek Viewers Choice Marathon aired 28 September 1991 immediately before the Star Trek 25th Anniversary Special. Like the special, it was hosted by William Shatner and Leonard Nimoy. There were ten episodes chosen for the marathon, which were shown in order from #10 through #1: "Balance of Terror", "A Piece of the Action", "The Menagerie, Part I", "The Menagerie, Part II", "Space Seed", "Amok Time", "The Doomsday Machine", "Mirror, Mirror", "The City on the Edge of Forever", and "The Trouble with Tribbles".

There was also a shortened version of the marathon shown in some markets which focused exclusively on the final three top-ranked episodes.

TOS Viewers Choice countdown

Nimoy and Shatner introduce each episode during the countdown