Most of these are not obscure, just older.
Hardware
http://www.youtube.com/watch?v=wyY_iX9UCE8
Nemesis
http://www.videodetective.com/titledetails.aspx?publishedid=617698
It's a B movie. But a B+.
Saturn 3
http://www.youtube.com/watch?v=ym-0d8lLqBU
Was good stuff in 1980.
Manhunter
http://www.youtube.com/watch?v=K7fofmn_l0E
http://www.youtube.com/watch?v=dqBDkXjQh2A&feature=related
Hannibal Lector before Anthony Hopkins did it again.
To Live and Die in LA
http://www.youtube.com/watch?v=v4cWGF4pPRU
Red Rock West
http://www.trailerfan.com/movie/red_rock_west/trailer
Battle Beyond the Stars
http://movies.nytimes.com/movie/4291/Battle-Beyond-the-Stars/overview
http://www.scifimoviepage.com/dvd/battlebeyond-dvd.html
Guess what similar star war inspired this turd.
But it does have that guy from the Waltons TV show.
Space Hunter: Adventures in the Forbidden Zone
sn.com/movies/movie/spacehunter-adventures-in-the-forbidden-zone/
Weakly scripted? Not when I were a lad.
A Boy and His Dog
http://www.youtube.com/watch?v=gu9fESAlGc4
Don Johnson as Mad Max, if Max was 17 and looking for girls.
Cool World
http://www.youtube.com/watch?v=GACDzexAdV0
Requiem for a Dream
http://www.youtube.com/watch?v=lgo3Hb5vWLE
Romeo+Juliet
http://www.youtube.com/watch?v=sMel13nY0PE&feature=related
Just 'cause I like it doesn't mean I'm (happy? Why can't I say that?)
Where The Buffalo Roam
http://www.youtube.com/watch?v=pEQOoNbZHVs
Idiocracy now, well...back then
Does anyone remember that monster movie from Japan 2 or 3 years ago?
A morphed fish/lizard thing trolling it up under a bridge? I'd recommend it if I knew what it was called.
All the best movies I have seen are foreign. Too bad I don't remember their foreign names.
So my list is mostly whatever B grade crap I do remember.
But one thing you might try is find out what modern movies are remakes of relics from the 70's 60's 50's 40's.
If you rent both versions and watch them back to back you see some interesting things. Because you are watching the same basic story unfold. But told from two different times, two different societies.
Yes the most obvious difference is special effects. But it also shows our obsession with quick visuals, and lack of substance. Often the older versions are better written, directed and acted. Because they had no bag of tricks to cheat with.(careful, they made stinkers then too) And usually the older they are, the better they get. Alternate video stores have good stuff from the 50's 60's for sexual/political equality. The 60's 70's for race recognition. Rapper Gang wanna'be Thug Hoodlums have nothing on Sidney Poitier. And he did it with class, with no posse.
We always think we are the modern generation. The most enlightened. But we forget that our parents and grand parents had the same social issues to deal with. And they usually did a better job of it.
There is a horror movie I am trying to remember. The modern version is strong on effects, but has no substance. While the older version has character and deals with homosexuality with far more maturity than we do.
We are not now as nearly as evolved as we were.
You mentioned Idiocracy. The sad thing is, that movie is terribly accurate. If you watch movies from the 40's,50's and 60's with brilliant dialog struggling with moral issues we ignore or are too embarrassed and childish to deal with, you will see how far we have fallen and so quickly. (In the Heat of the Night springs to mind,if I'm remembering the right film)
Particularly on topics of race and feminism. During the years of world wars, women had far more power and respect than they do now. Because the men were taken away for awhile. And women filled the roles.
I can't give you a list, because my memory sucks. But other people might be able too.
And there is always those old radio programs. The stories don't tell us much. Funny then is funny now. Suspense then is suspense now. But the commercial advertisements say allot about the culture they were selling to.
That's not always a good thing.