The Invasion of the Body Snatchers (1978) is also great

I like the Alien's but The Thing is probably one of my all time fav Alien movies.

I recommend the movie to anyone that enjoys old(er) movies

The original Alien also took some ispiration from an Italian Sci0fi movie called Planet of the Vampires, directed by Mario Bava

Incidentally, to circle back to John Carpenter, the first Alien is very similar to Dark Star - Dan O'Bannon wrote or cowrote both, and you can really tell. Watch Alien first, then watch Dark Star, then go back and rewatch Alien.

Yeah it feels like something I'd really enjoy, although 2 was great in its own right

Alien is the creepy isolation horror one. Aliens is the explosive sci-fi action one. Both pillars of their genres, very different in presentation.