One of the main reasons I got enthralled by Deadly Premonition, besides the obvious ones such as my love for twin peaks, weirdness, alternate world horror and original zombies, is the way the game uses Zach.
I've seen some mixed opinions and interpretations of Zach here, but most people seem to merely focus on his place in the plot and backstory and whatnot. I feel that Zack is one of the best attempts at bridging the gap between the player and the player character. A trauma-induced second personality that the protagonist confides in, consults, and ultimately hides behind when exposed to new threatening situations is in my opinion one of the best solutions I have yet to see. Amongst other things it enables some smooth plot exposition and gives the reason why, in this case, agent York is merely watching from the back seat as it were, while someone else is at the wheel.
I would love to see, or create, more innovative approaches to this. I've always had a soft spot for a mental second, but it mostly ends up being an antagonist... Which isn't always bad, but not what I'm out for.
The place of the player, and the general narration is something many games stumble and fall over, and not much innovation is present. It would be great to see more inspirational examples, or hear general thoughts on this as well.