Ah, yes. A classic. Or rather classics. The first is still the scariest in my book.
H.R. Giger, who's artwork is used in all the Alien series of movies, definitely sets the tone for what scary aliens might be like.
Some of the "funnest" SciFi, IMO, is found in the B-Movies. SyFy is having a running go at alien, monster and time-travel B-Movies today. Actually, they may be more D-movie given how bad they are.
