That's a good candidate--although this was once again a case of a better novel than a movie, and in my never humble opinion, neither of them all that good.
To that extent, 2001, a Space Odyssey
was good for exactly the same reason, that the "aliens" with whom (or which) we were dealing were not anthropomorphic, and not even perceivable as we might think we ought to be able to perceive them. The motion picture leaves you in doubt as to whether or not there has been contact with anything more than a machine, or a device.
The original story upon which it was based, The Sentinel
, was a "first contact" short story by Arthur Clarke which posited a device on the surface of our moon, which, when its "force field" has been breached, sends forth a powerful signal, and then shuts down. The idea, of course, is that an intelligence has now been informed that we have become spacefarers. That was the point of departure of the motion picture, and i liked that we were never expected to believe in little green men nor horrifying monsters--but rather, to accept what we might not be capable of understanding.