Duh, Square Enix.

All of them have a good chance of winning.

Nintendo: Has a lot of games that we know are coming, but know little about, such as release date, or gameplay footage. This includes Kart/3D mario/Zelda for WiiU and a bunch of 3DS games.

What Nintendo fans will say: Nintendo showed the largest amount of high quality games with the potential for good sales and pushing hardware sales.

What the detractors will say: Most the games they showed were games that had already been announced, potential criticism of the fact that a lot of the games are from established franchises.

Microsoft: Will surprise everyone who reads gaming journalism but doesn't read it in any detail by revealing that they never had intentions to make the 720 online required or not play used games. They have not been making any announcements about Xbox Live, whilst Sony has already shown their hand, and Nintendo have already played theirs. With Xbox TV and Durango running windows 8, there will be a lot of potential for interconnectivity between a lot of MS devices. Will likely have 1 big exclusive announcement, which will contain either halo or gears in the title.

What the fans will say: No-one can compete with Live, consequently all the big multiplats will sell best on Durango. MS will dominate due to the PC/Xbox TV/Durango/Windows Phone combo. Showed the most new information (due to reveal of the console)

What the detractors will say:
* Shooterbox will fail outside of the English speaking world, particularly Japan.
* Networking with Windows 8 would be good if anyone actually used W8
* Apple TV will stomp all over Xbox TV.
* PS4's slight technical advantage means Durango is d00med!

Sony:
Will reveal full details of their console, if they can stop it leaking beforehand (See every other recent Sony gaming hardware reveal, PSV, PSP:Go, Most of the PS4 info). Will announce a bunch of games that have amazing graphics, but aren't available for the launch window, but that, like Heavy Rain etc, have little sales potential. Price will be announced and it will be high - Sony can't afford to take a huge hit on PS4 consoles when they:
a) Aren't pushing a new disc format
b) Don't have the PS2 continuing to print money. PS3 is doing well, but it's no PS2.
c) Are in such a dangerous financial position.

GT6 details, which had best include a Nov 2013 release date.

Media Molecule game announcement, I'm thinking probably Now 2013 release of a game that isn't a LBP main series, or potentially LB main series for first half 2014.

Uncharted for 2014, will look amazing.

What the fans will say: PS4 hardware is the best, Sony has the most new IPs and the best looking games.

What the detractors will say:
* Nothing that can save Vita.
* No big games for PS4 - launch will be like PS3.

So you expect.... WONDERBOOK 2!

MEGATON!

If MS keeps quite all the way to E3 they could steal the show with the only hardware announcement at E3. But I think they will announce in the next month and be in the same boat as Sony for E3.

I voted for Nintendo because they'll surely show new info and trailers of the Monolith Soft new game and maybe Zelda WiiU and I want to see the new Mario 3D and Mario Kart U in action. They´ll surely show a lot of info on many games.
But MS and Sony will show new consoles so they have a very big possibility to win, however if Sony says something like: PS4 will cost $499.99!! or MS says: Always on AND always connected then they can loose the E3.

And I'm looking forward to the Square Enix presentation because I still have hopes that KH3 will be announced this time, no matter for what console.

I will

GAMERS

It should be a great few days for everyone. Microsoft is the big question mark. It could dominate the show with a bunch of huge revelations and exclusives games, or it could place last, like it did last year.

Sony, I'm sure, will perform well, especially if Tretton is running the show. He knows how to work a crowd and, more importantly, he knows his audience and the strengths of Sony's products.

But if I was a betting man, I would put my money on Nintendo. It needs to drum up enthusiasm for the Wii U and keep momentum going with 3DS. I expect to see a lot of software: Mario Kart, Super Mario 3D, Super Smash Bros., Monolith Soft's "X," Retro's project, Yarn Yoshi, Wii Sports, plus a few games for 3DS, including Metroid, Pokemon, and the Monolith Soft portable game.

Then ethomaz is right.

I don't care who wins, all I care about is seeing what Nintendo, Microsoft, and Sony has to say good or bad.