Nintendo finally nailed it this year after a string of disappointing E3s. The 3DS would be exciting even without the 3D stuff, they're making possibly the cutest Kirby game yet (with elements of a favorite franchise of mine, Paper Mario) and although it's not really them making it, that Epic Mickey looks sweet. 
 
Sony's show was perhaps a bit longer than needed. They have a habit of padding everything out with huge speeches when I'd rather just see the damn games being played. They had some cool announcements, Portal 2 is a pretty good get, Twisted Metal was genuinely surprising (or rather, Jaffe's involvement was) and Kevin Butler was excellent. 
 
Microsoft had a rather hit-or-miss show. The big Xbox Slim announcement was totally expected but they made it exciting anyway by pulling a Saturn and an Oprah. Kinect did not show well - where the hell was Child of Eden? The new Dash stuff looks cool (Zune Pass!) and the Rising trailer was brilliantly violent. 
 
EA has a structure for their shows at this point and it works well. They go through games one by one and demo them, they have the Sports bit with Peter Moore and then the Sims bit, finishing up with the Partners bit. It's not a showy, MTV presentation, they just show people what they're their to see, and I love that. 
 
Ubisoft. Oh man. Child of Eden was cool. So was Rayman Origins and maniaPlanet. The rest was utterly surreal, but even that was challenged by... 
 
Konami: Exteeeeeeme.