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.
YMMV: Alien Nation
Fridge Horror: More than likely, the Overseers are going to come for their former slaves sooner or later. Who's to say that they won't decide to subject humans to the same fate as the Newcomers?
This was the plot of the first TV-movie, and was only averted when the advance leader, Ahpossno, realized that he had repaid kindness the Earth-bound Newcomers had shown him with treachery and deceit, and they had in turn ensured he would never live to see the enslavement of Earth.
In the series, there was an episode where overseers tried to contact a probe that came looking for them. They missed, but it was damn close. The overseer who tried to do this explicitly referred to the human population as cargo, just like to the Tenctonese, so the overseers WILL try to kidnap all the humans as slaves.
Mary Sue: With the arguable exception of the Overseers (or Kleezantsun'), the entire Tenctonese species (or at least the genetically engineered former slaves).
Screwed by the Network: This show's trajectory eerily mirrored Firefly - It aired in the Friday Night Death Slot and got an insanely devoted fandom. Henry Jenkins even cited it in Textual Poachers as a unifying force for different factions of Fan Fic writers (those who were writing for sci-fi series, and those who wrote for action-adventure series). But this show was the Trope Codifier for Fox treating their cult series poorly.
Fox didn't even want to cancel the series but couldn't attract enough advertisers to support the show's considerable budget. The movies came out because several new executives hired at Fox were fans of the series themselves.