Ghostbusters said:

The Terminator franchise is an excellent example on how to turn a terrible concept into a fantastic movie by just using good writing and directing. The story is about a computer called skynet, sending a robot back in time to kill the mother of the child that will basically destroy skynet by starting and leading a rebellion against skynet's genocide of the human race. It sounds like the story of a cheesy Saturday morning cartoon. So many things could have gone wrong but James Cameron pulled off a believable, dark, exciting movie by using good acting, casting, cinematography, writing, and special effects.

I agree the execution of the story was very well done, but I disagree that there's anything wrong with the concept. It's an excellent concept, stolen from a top writer. It's a fascinating idea, full of dramatic situations, genuinely scary, not as cliche then as it is now, and I really wonder what Saturday morning cartoons you watch.