I think this was Nintendo's year at E3.
3DS: When I first heard about 3D picture on a handheld without glasses, I couldn't believe it. Now, however, it's a reality. With all the E3 goers going ga-ga over the system and saying the 3D really works, plus all the announced titles, the 3DS will hopefully bring a new handheld experience (which I desperately need).
Sonic Colors (Wii): Again, when I first heard about Sonic Colors (or Colours

), I said, "Pfft what are they thinking? It probably won't be that great." From hearing what people had to say about the Wii version, it sounds promising. Generally speaking: Sonic Unleashed - Night stages + more speed = Sonic Colors (from what I've heard). Haven't heard/read much on the DS version, so I don't have much of a say on it.
Portal 2: Need I say much? It's been pretty much covered already. Portal = awesome. Portal 2 = awesome 2. It's basic math.
Honorable Mention:
Goldeneye: Hearing that there was a new Goldeneye just flat out made me happy. From the trailer, it looks like a true sequel/remake of the N64 classic. Personally, I like how the game graphics are. They kinda give it a more Goldeneye feel to it. One only gripe I have is that they modeled Bond after Daniel Craig. If they put Pierce Brosnan in as a playable character (hell, even an unlockable), I'll forgive them.
And just a mention:
Xbox Kinect: So Microsoft creates this awesome technology. A sensor that can detect bodies, motion, and tracking. Basically, a Wii without the Wiimote. Unfortunately, it feels like it's following in the same footsteps as the Wii. In other words, it feels like the Kinect is being "milked," so to say. For example, using Kinectimals to demonstrate user recognition and interaction. Not bad, but I don't like watching
an 8-year-old girl talk to her pet tiger, Skittles to see this being demonstrated. So wrapping this all up, the Kinect is great technology, but I'd like to see some more potential titles that can show what it can really do, like a fighting game or something.