Skyrim seems like something he would enjoy. With god mode, and other such ways of enhancing the exploratory side of the game. Play it on a high end PC, with a few visual enhancement mods.
Minecraft the man likes to build I'd love to see what he'd make
Journey the ps3 game with no talking and all it is , is exploring the amazing world with small puzzles and just watching a story unfold
Exploration without risk of difficulty from mechanics obtruding the experience:
Mass Effect 3 on Narrative mode.
Dear Esther for sure.
The problem with Bioshock or Skyrim is that he'll probably have problems with dual analog in a first person game. He wants to see a world and not be held back by his own deficiencies with the mechanics, so you need to stick to experiences that will not get in the way of that. First person games will for sure.
Halo, Braid, Mass Effect, these would be some good ones.
I'd say Minecraft and Nuts and Bolts are the only ones he could really get into without going way, way away from the mainstream. Halo is certainly not the game for him.
Journey is a must to me, and in one sitting. It might be a game he should play alone and give his thoughts afterwords. If he has cameras and people around asking about the experience, it may just ruin it.
Journey was the first one that came to mind with me. The mechanics are simple, the world is gorgeous and it's an experience that you can't really get from any other medium.