I agree on the empty sockets, they are a very creepy image.
I was always really big on the Alien being so very alien to me. Unfortunately when you think about it, they facehugger itself is practically designed for a human head, not a Jockey. Also now with Prometheus, Ridley has linked both the Alien and the Engineers directly to humanity, now sadly much of that "alien-ness" is now lost for me, probably forever.