Me, personally, it would be:
Silent Hill 2: Because i want to see something deep and dark, and i want to make the pacman player cry.
Metal Gear 4:show them depth of gameplay,some story, and of course, graphics to blow their mind again
and
Gta4 to show them a huge breathing world (i havent played rdr yet.
It would be like virtual reality to them. Do you guys think theyd even see the flaws and details?