Actually I tend to think of the syndicated third season of the '80s series (whose writing staff was anchored by J. Michael Straczynski, a pretty good Serling mimic) as virtually a different show from the first two seasons on CBS. So maybe five and a half versions.
Oh, and I gather Leonardo DiCaprio is developing a TZ-branded movie, although it would be based on just one TZ episode rather than being an anthology like the previous movie. Plus Real Steel
was based on a short story previously adapted as a TZ episode.