Overused plots
I have been a Star Trek fan since I was 7 and loved it, but now that I am old man and I am watching reruns and I am saddened by how many times they have used the "simple people worship a god/obelisk that is really a computer"
Or how about the computer/robot that either cannot understand love or is asked a schoolboy paradox riddle and then goes into a loop and starts to smoke.
Sheesh.