Battlefield 4
A really short demo compared to the conference slice and disappointingly this was not playable at the Microsoft booth. This is the Angry Sea mission, where your ship rips in half and you navigate towards a Chinese cruiser - on top of which you fire at the shacklings of aircraft and they go sliding down the tilted deck of the ship. Absolutely spectacular, but nothing compared to the exploding skyscraper of the multiplayer demo.
1080p at 60FPS is being targeted on Xbox One, and also 64 players in multiplayer - both of which set it apart from previous console versions. When pressed, the Microsoft reps admitted it's running from a debug environment designed to the console's specs.