Alien is a classic. It's cold, mystifying and contains one of the best creature designs of all time. (I prefer the Director's Cut)

More in keeping with the original atmospherically, Alien 3 took studio problems and interference and got creative with it. It uses tragedy as horror perfectly and concludes Ripley's arc with triumph. (I prefer the Assembly Cut)

While they're all money-makers, Aliens took the more blockbuster approach and departed from the hopeless and dark feeling of the first one. Aliens is a great action film but I think it set up the wrong expectations for every other film to come. (I prefer the Theatrical Cut)

Perhaps the most underrated entry in the series, Covenant mixes biblical elements into the standard Alien plot line and is the most philosophically interesting in the series. The first 20 minutes are a bit bumpy but its not much to complain about.

Prometheus is a film full of great ideas that's just under cooked. The team of writers are known for this and had they been replaced I think this would have been a lot better.

One of Paul W. S. Anderson's best films (not saying much). AVP is completely muddled but an entertaining romp that's not canon at all so there's nothing to get mad about. The unrated cut is worth a look.

A complete failure in reviving a franchise. The humor falls flat and doesn't make it feel fresh in the slightest. It doesn't matter what cut you're watching, nothing saves it.

Terrible even by B-movie standards. Mean spirited and lacking in just about every category. Not even a "so bad it's good" kind of movie. Don't let morbid curiosity take over, avoid it at all costs.