Ranking is tough. My rankings are chronological (Alien, Aliens, Alien 3, Alien: Resurrection). Covenant is at the end somewhere with A:R.
This is easily the weirdest Alien movie ever. The first 20-30 minutes are great, then it is all pure bat-shit insanity. I am not sure how anyone could think back after seeing this movie and not shake their head in amazement at some of the shit that happens in this film. It is almost "wooden planet" type bonkers.
Rating: 5 WTFs out of 10.