Comment 2001 (Score 3, Informative) 438
No noise in the vacuum of space?
Bowman's head not exploding when he has to blast himself into Discovery's airlock?
The fact Discovery has an area that rotates fast enough to simulate 1G for the sleeping crew as well as Bowman and Poole to keep from losing bone mass?
The trip from Earth to the space station (the latter of which had to rotate to also simulate 1G)?
Lensed in England by Stanley Kubrick, and still pretty damned accurate, especially since this was Arthur C. Clarke's work we're talking about here.