Difficult choice. Both are amazing. Still have to give it to the original, the atmosphere and the way the creature is shown, or not shown, as well as the layered plot (seems simple on the surface, but gets deeper once the actual motive of the company is revealed), which all makes it one of the best horror films ever made, appeal more to me than the more straightforward Sci-fi action of the sequel. But like I said, the sequel is almost equally amazing, both far above the rest of tue franchise, though I do like the third movie as well and even appreciate the fourth, Prometheus and the new one from a couple years ago. AvP is okay for what it is, but the sequel to that is dreadful.