I was always a big fan of the original couple of Alien movies by Ridley Scott. Once you got to Alien 3, it started to get a little tired and by the end of the series, it was just plain bad. I was a little apprehensive when I heard that Prometheus was going to be a prequel to the movies, but it turns out to be pretty good.
It did very well in theaters and a sequel to the prequel has already been slated with some of the original crew coming back. Many people didn't realize that this was directly connected to the Alien movies, but after watching it you'll definitely see the connections.