This is seriously going to be the best E3 in years.

Considering Sony has won (for most people) the last 3-4, E3s I think they will win E32013 too. M$ will be a close second though.

Winning E3 doesn't hold much relevancy anyways. It is just another industry trade show.

A combination of:

First, who has the best conferance?  This can be determined by, the most new info/reveals, most 3rd party/indie support, positive vs. negative news.

Then, who gets the most actual gameplay/playable games shown?

Finally fan/media reactions.

Problem here is what outweighs what in importance will vary amongst peeps.

We? The King decides.

well the Halo 4 demo didn't help them win the last E3. But it could be a different ball game since it'll be on much more powerful hardware 

Gamers win. All of them.

Whether you prefer Sony, Nintendo, or Microsoft, you win. Whether you're into inFamous, Smash Bros, or Halo, you win. Whether you own a Vita, Wii U, or 3DS, or plan on buying a PS4 or 720, you win. If you game primarily on PC, you win. We all win.

lol but seriously probably Sony. They'd have to mess up pretty badly to not "win." Though honestly Nintendo is practically bowing out, they could have held Zelda for E3, but they didn't. You know they'll probably hold back some other things only to reveal them weeks later in a Nintendo Direct.

i just hope it is better then E3 2012 out of all the E3 i have seen it was the worst there was only conference i thought i enjoyed which was ubisoft's

explain cause they usually have the worst out of the 3

FIFA will steal the show.