Alien
It's my favorite of the franchise. As good as Aliens is, I just adore the tension driven horror plot of the first one. The set and character design is incredible. Truly it is difficult to imagine science fiction absent of Alien. To bring space travel down to such a pedestrian and blue collar level is such a brilliant decision and I think it must have influenced everything outside of Star Trek and Wars since. The 45th anniversary remaster playing at regal was perfect and the film is just as much of a classic as the other 50 times i've seen it.
Anyway, I'll watch whatever Ridley Scott makes.