for me it was actually alien 3.
I also knew the predecessors and thought they were really good, but I was a horror and science fiction fan in general and the focus wasn't yet on Alien.
Unlike many others, I thought it was a smart decision to have just a single alien instead of hordes of them.
When the film came out in 1992, I was disappointed at first, but then I realized that the film was merciless and had the most aggressive alien, with what I thought was the most elegant design. Not so well implemented in the film but still cool.
I watched it several more times in the theater and eventually became a fan of Alien 3 and the entire franchise. The assembly cut made all of this even stronger.
Since then, the topic of ALIEN has stuck with me and I think that of all the well-known brands that have been messed up in some way, Alien has remained the best.
Even if the alien designs in some films were no longer that good (Alien 4, AVP-R,) and in most comics they were downright crappy, I think that the alien itself is the greatest film creature of all time and will never be topped.
As for Predator, I saw the first film when it came out on video and thought it was great.
After Alien, the design was the best there was to date.
I liked the sadistic arrogance of the hunter who turned the tables and hunted people.
I liked the second part just as much as the first and the design was great here too. only the ending was weak
Although I have to say that the code of honor introduced here is nonsense and doesn't suit the predator at all.
Anyone who thinks about it a little more closely will recognize it.
After that, nothing good came out of the Predator universe for me personally. With the further films and explanations came more and more inconsistencies in his behavior and existence. That's why I'm still limiting myself to the first two parts at the moment.
avp films, games and comics as a fun change is nice, but I would have left both of them their own universe and not done any crossovers.
