Not the best of the show or the worst...just the titles that I actually was able to play that caught me by surprise.
 
Biggest Disappointment: Mafia 2
I was so looking forward to this, ready to pre-order and everything.  After ten minutes of playing the demo 2K no longer gets my money.  After Red Dead Redemption, this type of stale gameplay will not pass.
 
Biggest Surprise: Splatterhouse  
Where did this come from? I had zero expectations before playing it and by all rights should have lost interest in this uninspired throwback to the PSOne in about a minute.  But this ultra gory beat-um up kept me going back to replay the demo over and over.

Biggest Disappointment: Valve's "surprise".
Really? That's it? You've reopened communications with Sony? Most of your fans are on PC, so you build us up for a "big surprise" to reveal that you are developing games for another platform? 

Biggest Surprise: Rage
Game looks very good and has a hell of a lot of style. I don't believe a lot of the hype about it, but still, I can't deny it looks good.

Biggest Disappointment: Zelda: Skyward Sword
They said that Zelda was right for some innovation, time to change things up. What did they change? Add Wii motion plus and give Link a whip and bug cannon. What the fuck Nintendo, fuck you! 
 
Biggest Surprise: Gabe Newell's appearance at the Sony Press Conference
Gabe was such an unmovable wall for Sony for years and to have him come on stage like that, made this one special conference.

Biggest disappointment : Microsoft press conference
I am a microsoft fan through and through and have always owned and played xbox but this conference was boring, uninspiring and just lacking so much.  Kinect is not enough for me, and another Xbox is all well and good, but its just another xbox 360
 
Biggest Surprise : Nintendo 3DS
 It might be just a personal thing but this really captivated me.  I'm not bothered about the 3d aspect at all but that list of developers on board, the extra power and the general look of that thing is very exciting.  I was just expecting another DS with crappy 3rd party support but with that level of software development potential it could be amazing

Biggest disappointment: PlayStation 3's Move
I wasn't really disappointed by anything, but the announcement I found least interesting was the Move controller for the PlayStation 3. It didn't impress me at all, and it's obvious they're just trying to steal some of Nintendo's success with the Wii. Although I can't blame them, I just don't think this device will be worth getting.
 
Biggest surprise: Driver: San Fransisco
With the exception of Driver 2, the past Driver games haven't been too great. I thought they had given up on the series, so not only was I surprised to see a trailer for another sequel, but I was very impressed with what they've done with it. I'm really looking forward to hearing more about this game.