As a couple of folks (including Stan Tychinski and Fred Hembeck) have informed me, the full list of The 100 Most Memorable TV Moments is not a grand secret. It was printed in full in the current issue of TV Guide. I rarely read past the first few pages of that magazine unless the checkout line at the market is unusually long.
I know it's silly to quibble with any list of this sort, but I could only think of two "moments" that surprised me in their omission. One was Walter Cronkite announcing the death of President Kennedy. The other was President Johnson surprising the nation and newsmen alike with his announcement that he would not seek a second term. The entertainment ones are too subjective to weigh, but Kennedy's death and Johnson's abdication were actually instances where, on live TV right before your eyes, you could feel the world change.
And of course, I'd have tossed in my first screen credit. That is, if historians haven't bulk-erased all the old tapes of The McLean Stevenson Show.