Microsoft: 9/10
Sony: 9/10
Nintendo: 7/10
For the first time in E3 history for me, and it seems that others agree in this thread as well (more than ever), everyone wins. I'd have to go with Microsoft winning E3 if I had to choose. Project Nadal, Twitter, and the Facebook parts of MS's E3 were the obvious lows, but everything else was amazingly presented. Alan Wake looks amazing, HALO ODST, as well the defining moment Kojima announced the next Metal Gear for 360 (although it will also come to the PS3). I'll save the boredom of recaping what happened at E3 as everyone knows what happened already and go on with saying that it has never been a better time to be a gamer than now.
Quiet Storm = Best Gatorade flavor EVER.