It would really depend on what type of interests the person had. If it were someone who liked Action, COD or Battlefield. Adventure, I'd suggest the Uncharted series. Sci-Fi would be Halo or Mass Effect. Fantasy would be Skyrim. For Horror, the Resident Evil, Silent Hill and Dead Space series would need to be included. If they liked LOST I'd suggest the Bioshock series.
It would really just depend.
I guess as of right now, I'd go with Bioshock: Infinite. It has a bit of all of the above, blending action, adventure, suspense, sci-fi and fantasy, along with a great story and relationship building. The voice acting doesn't take you out of the moment and you develop a genuine interest in seeing the story through. It's a total package kind of game.