Good Sci-Fi movie that predated the Matrix, but had a lot of the Matrix ideas in the film. The use of Nanites, micro-machines, to grab molecules and build something that looks and acts alive is very fascinating. It stars Denzel Washington who is a good cop in jail with a false charge who hunts down a Nanite human killing machine. Very fun plot twist at the end that will fake you out.
Think of the Matrix immortal killers brought into the real world having all of their Matrix tricks and powers.