In the seemingly never-ending debate as to whether games are art or not, MGS is an example I always quote when making the point that, yes, indeed, they can be. It breaks the fourth wall on a regular basis (for instance during the Psycho Mantis fight) and requires the player to reflect on his or her virtual bloodlust. For the sake of sounding hopelessly pretentious, it's probably the first postmodern video game ever made. Oh, and it's rather awesome too.