These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Remember Goldman from "The Big Hammer"? Well, his call sign is 1-Adam-12, which means he's Malloy's partner who was KIA not long after.
In the intro to "The Big Kidnap", when Friday is talking about how most people work to earn a living, one shot is of Ed White's spacewalk. The day after the episode aired, White and his two crewmates for a pending mission, Virgil Grissom and Roger Chaffee, died in a tragic fire.
In the movie, Streebeck has a hamburger phone in his apartment. Twenty years later, the hamburger phone would make an appearance in Juno and became a small meme for a while (even leading to a spike in hamburger phone sales). However, Streebeck's phone seems to work much better.
Hilarious or Harsher in Hindsight: In the third season of the '60s series, one episode dealt with Friday and Gannon's efforts to recruit more minorities into the force from a group of high-school graduates. One of the prospectives is none other than one Orenthal James Simpson.
Narm: This might have been horrifying back when the first episode premired, but the introdction of the first perp (of the 60's revival show) they bring in might invoke humor. They find a young man with his head buried in the ground, but clearly alive. Friday and Gannon bring his head up...to shockingly reveal one side of his face is blue and the gold with a dramatic scare chord!
Narrowed It Down to the Guy I Recognize: Averted on the '60s show. Jack Webb used a regular group of actors to play various roles, (see You Look Familar on the main page) and in such a way that even if you did recognize that person from a previous episode, it was just as likely as not that the character would turn out to be the episode's perpetrator. However, most of the actors had a 'type' of character they were known for playing, and you could reliably depend on the knowledge that if a character had played a cop before, he was playing a cop again, or if he had been a non-cop, he wasn't likely to be a cop this time out.
Retroactive Recognition: Greg Brady is an altar boy in the third and final version of the 'red wagon for Christmas' episode (which was done on radio and both TV versions).