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.
Aside from the obvious, one episode ended with the possibility that there might be a Terminator in your walls. Right now. He's been there for decades. He's armed. And he wants to kill you. The fact that the Terminator in the episode was hiding in the walls of an old, abandoned hotel isn't actually better; think of how many buildings in your area are old and under renovation. Think of how many old government buildings there are, period, that you have to use.
There are Terminators who wear the faces of your family and friends, the ones who can change their looks at will and slip under doors and sprout ten-foot blades, the ones who can appear literally at any time and in any place, the reprogrammed "good" ones used in every resistance base who can flip out and revert to their Omnicidal Maniac default setting at the twitch of a circuit, the one standing right behind you right now...
And then there's the possibility that the love of your life is actually just an emotionless machine specifically calibrating their every action to make you fall in love with them, just to get themselves in a position to complete their mission. And they'll kill you once that mission is over.
Too Good to Last: One and a half seasons, and it ends on a severely aggravating cliffhanger (albeit one whose followup they probably wouldn't have had nearly the budget to pull off properly).
Uncanny Valley - Cameron, Cromartie, and just about all the other Terminators look very human, but their behavior is... off...
Riley, of all people, starts becoming one of these later on, once her history as a resistance fighter from the future becomes apparent. And doubly so when it's revealed Jesse is psychologically abusing her and deliberately trying to get her killed.