Russell,
 
It's a ridiculous bit of high Hollywood anti-communism, but _Red Planet
Mars_ (1952) certainly intended to portray a positive future, in which
Communism has been vanquished and religion rules the earth.  It stars a very
young Peter Graves.
 
A similar, but less ridiculous, film is _The 27th Day_ (1957 . . . I think),
in which Communism is vanquished through the help of alien intelligence (again,
it's not necessarily what all of us would see as an overwhelmingly utopian
conclusion but it was certainly intended that way).  _The 27th Day_ does not
display its red-baiting side until the very end and is simply a better movie
than _Red Planet Mars_.
 
Hope these are of some help,
 
Ben Alpers
Princeton University