Westworld. The first thing that caught my interest was that it was written directly for the screen by one of my favorite authors of the genre, Michael Crichton. Not only that, but it was directed by Crichton too, his first Hollywood film! So we already have some historical significance there, but was it any good? I would say yes, quite good, thus exhibiting Crichton's natural ability for both screenplay writing and film directing very early on in his career.
Westworld is about an expensive amusement park which promises an experience like nothing you've seen before, but then something goes terribly wrong and causes all sorts of mayhem. Sound familiar? Yes, it is the exact same story structure as Crichton's much later novel Jurassic Park (1990). In Jurassic, he explored the possible dangers of an emerging technology of the day: genetic engineering. In Westworld, he explores the possible dangers of an emerging technology of that time: computers. In 1973, personal computers were still a few years away, so Westworld was run by a fully staffed underground central computer facility. That facility controlled three fantasy lands: an ancient Roman city, a medieval castle, and an old American Western frontier town. These were populated with lifelike robots that guests could interact with in whatever ways pleased their fancy, all for $1000 per day (this was before the hyperinflation of the late 70's). It's not a very complex plotline, but it contains enough originality and enough well timed suspense to keep it moving along. Although it is strange to see Yul Brenner as the menacing robot, he plays it almost perfectly - not too human, but not too robotic either.