Just thought I'd start a thread about this topic.
John Carpenter's The Thing (1982) was a great film, one of his best IMO. For me, it's right up there with Alien (1979) as one of the greatest sci-fi horror films ever made. And yet one film made anything between $100 - 200 million at the box office whereas the other made only $19 million. Carpenter's classic was unlucky to be released at roughly the same time as E.T.
Here's another example: Near Dark (1987). It's a vampire film without fangs, crosses, holy water, garlic, stakes, coffins ... even the word 'vampire' isn't said in the entire film. Although I don't have much experience of the vampire sub-genre - the only vampire films I've seen are Dracula (1958), Fright Night (1985), The Lost Boys (1987), Near Dark (1987), Fright Night Part 2 (1988), Bram Stoker's Dracula (1992) & John Carpenter's Vampires (1998) - I feel ND is right up there with the best. For me it's the best vampire film I've ever seen. Lance Henriksen is very good as Jesse. And Bill Paxton's performance as Severen - wow!
Those of you who've seen it will know what I'm talking about.
Near Dark was made on a budget of $5 million; it made only $3.5 million at the box office. This was perhaps another case of two very good films being released at roughly the same time - in this case it was The Lost Boys. I like The Lost Boys but I feel it's a tad overrated.
At least The Thing and Near Dark have enjoyed great success in video rentals and VHS/DVD/Blu-Ray releases.