My money would be on Nintendo this year. I say this because much of the content for both Sony and MS will be exactly that for both. Nintendo will have the most exclusive content. And that content looks to be interesting. The key is that:
-Zelda U is very good-looking and mature.
-X is shown in all its glory, gets a good title and date.
-Some new IP's are shown that use the Gamepad in a fun way and get mainstream interest.
There are also some potential wildcards there, like a price drop or remodel (Wii U or 3DS), a new collaboration or a Mistwalker RPG.
My second choice would be MS, but I think they blew their load a bit early with the new One SKU and talking about Halo, etc, not unlike Nintendo last year when they felt the pressure. But they could still have more to surprise.
Sony finishes last, not because I think they will do poorly, but because when you are on top expectations are higher. The other two have more opportunity to surprise and shock, and shake up the establishment.
