For realistic (ie not idealist) view of the future, it has to be "Blade runner", one of the best sf films of all time.
For deep space exploration, "Red planet" is quite good, and "Dark Star" is just brilliantly darkly-humourous. "Silent running" is a real cautionary/eco-tale in space, and I would also recommend, on certain levels, "Event horizon", though in fairness that's more of a horror-story-in-space than a scifi movie...
Oh yeah, and another good "future" movie is "Logan's run", though again how you can quantify the depiction of the future as "realistic" is hard to imagine, since the future by its very nature is unknown to us. If you mean movies that show NOW, as the future, and are close, then ok, but otherwise it could all be true, couldnt it?