What was the one season show that involved giant creatures living in the ocean that were so large that they eventually ate all the whales and made them go extinct? They were so hungry that they began attacking ships at sea, and, thus, were becoming a danger to the human race. The last epidode's cliff hanger was when we got to see what they looked like.

Battlestar Galactica was actually set in the distant past, but you don't learn that until the end of the very last episode. Sorry for the spoiler. The meaning of that fact blows your mind.

Humans (8 episodes each for 3 seasons) was very engrossing, about robots that were exactly like people in every way, except without the capacity for emotion. Used as servants, it delves into both sides of the controversial concept. Well worth streaming.

I am surprised that "Humans" was not included. It was a compelling story of robots that look exactly like people in every way, without the capacity for emotion (until the end of the 3 year, 8 episodes each, season), that are used as servants. It pretty much delves into most, if not all, of the implications of using "synths" (as they were called) as servants - inches away from the concept of slavery, though they were never mentioned as such. The series was about both sides of the issue with an engrossing plot line. Well worth streaming.