Jeff Bridges in Tron:LegacyArnold in Terminator: Genisys.
It might no always be so easy, however.
USC Institute for Creative TechnologiesImperial College London
Using a custom rig that captures images of a subject's face at a resolution of 10 microns, these researchers have been able to capture the subtle ways that our skin moves as it wrinkles and expands, down to the level of pores.
With this advance in sophistication, the Uncanny Valley feeling you might get when watching a well motion-captured film only grows, as it becomes more difficult to distinguish between the computer-generated image and the real thing.
This level of graphic quality is still new, so it's not likely to see it used on a wide level for television or film, though it may come to video gaming sooner than those. Increasingly, games have been pursuing higher and higher levels of graphic quality and immersion through recognition, and so this is the logical escalation of that ethos.