Nintendo: B+ Lots of announcements and unveilings, good unveiling for the 3DS. Reggie needed to talk less, and I don't care how "epic" your sales are or how misinformed "the haters" are, so just shut up about it and show me more Metroid footage. Also, the new Zelda was disappointing, but at least they showed it.
Sony: B- Good games and some good announcements and surprises, but it was about 45 minutes too long. Like Reggie, Jack Tretton needed to talk less, and there were too many promo videos. That's not what people watch E3 for, they watch it to see new games unveiled, and see the games they know about demonstrated. It was overall a good show but it got boring and Sony needed to either cut the fat or find some more announcements to make. You could have started by showing Last Guardian.
Microsoft: D- Pretty much an epic fail. The only reason I didn't give them an F was because they showed Halo, Gears 3, and Metal Gear Rising which many people were excited to see. Kinect was an embarassment and Microsoft should be ashamed of themselves. When the biggest things you talk about during a GAME show are your console's NON-gaming functions, you've got a problem! And again, I cannot stress enough how disappointing Natal looks. It looks like Wii back before it had any good games, except even worse.
EA: B A good show all around. Lots of good games and a strong emphasis on the core gamer. Dead Space 2, Need For Speed Hot Pursuit, and the pre-rendered Old Republic Trailer were sweet.
Ubisoft: D Although it was worse than Microsoft's show, I gave Microsoft a lower grade because Ubisoft's show always sucks, and I didn't expect that to change. They met my expectations by sucking as usual, whereas Microsoft dropped the ball in a really major way with their overemphasis on Kinect and the 360's non-gaming functions. Ubisoft was just plain boring with lots of shovelware, so it was a typical SNAFU for them.