I prefer the original movies those two were based on.
In the case of "Alien" that would be.
It! The Terror from Beyond Space (1958)
And for "The Thing" it would be.
The Thing From Another World (1951)
Well, I wouldn't quite agree with that. "The Thing" was a remake of "The Thing From Another World" and was always declared a remake of that movie. Whereas "Alien" was neither based on "It! The Terror from Beyond Space" nor a remake of that movie. This rumor exists since some representatives of the studio that made "It!" sued the producers of "Alien" for alleged plagiarization, which never stuck. One of the writers of the first draft of the "Alien" script named "It!" as one of his many influences, but that's about the only connection between these two movies and it's very slim. That's like saying "Pirates of the Caribbean: The Curse of the Black Pearl" is based on "The Black Pirate".
I like both movies, "The Thing" and "Alien" very much. Both are amongst my favorite movies. I've seen both of them many many times.
But to answer the question, which movie is better, I'd have to say "Alien". The movie was made under considerably more pressure and still was a bigger success. It works from the first to the last second and there are no "holes" in it (like logical errors or holes in the plot). "The Thing" may be a great movie, but I can name two holes in it off the top of my head.
The most astounding thing I've learned about "Alien" so far is that Scott had even seen the future of this "franchise" long before it got picked up for a second movie. He already had shot scenes showing the "lairs" aliens build with human beings pinned to walls, but had them cut later for the cinematic version of the film. And we all know that James Cameron later showed exactly that in "Aliens" as the next logical in presenting more information about how these creatures live and procreate, although he had never seen the scenes Scot had left out of "Alien". There are not many director's who bring that much foresight, vision and dedication into their movies like Scott brought into "Alien". As much as I love John Carpenter and his remake of "The Thing", I have to pick "Alien".
invader said:
Can't deny 'Alien' has influenced cinema perhaps more than 'The Thing' but i'd also hazard a guess that 'The Thing' was made on less money & in a shorter amount of time too.
Well, an understandable guess, but not tru. The real "production time" (that means without the time from the writing of the original screenplay to the signing of contracts) for "The Thing" and "Alien" are about the same and the production costs for "The Thing" are estimated at about 1 to 1.6 milion Dollars more than those of "Alien".