I know it bombed back in 1973, but Westworld had a great concept. Like a precursor to Total Recall, it was set in a futuristic world when people could go on immersive virtual vacations and do anything they want to with no consequences. There's Medievalworld, Romanworld, and Westworld. In Westworld, they can drink at a saloon, frequent a cathouse, rob a bank, and kill people in a duel. There's no risk that they themselves can get harmed, because every weapon has a safety feature that it won't fire on anything with body heat. All the other "people" in the vacation are actually robots, and the whole environment is controlled by a bunch of computer programmers in a lab. It sounds amazing!
Of course, since it's a thriller, and a Michael Crichton movie, you know something's going to go wrong. When James Brolin, Richard Benjamin, and Dick Van Patten go on their vacation, they start off having a blast and doing everything they want to. While drinking in a saloon, Richard gets taunted by robotic gunslinger Yul Brynner, whose entire programming consists of picking fights and shooting in duels. Richard shoots him, and in the night, Yul and the other "dead" robots are dragged back to the laboratory, patched up, and sent back in the morning. Gee, I wonder what will go wrong. . .
If you're expecting a 1973 sci fi thriller, this is a pretty good movie. It's definitely entertaining, and could have even run longer than its ninety minutes. I understand why it had a couple of spinoffs and sequels. Try Westworld and Logan's Run for retro sci fi night!