1) Sony
2) Shared Nintendo / Microsoft
Of the two runners up Microsoft had the most impressive titles, but nothing we hadn't seen before except for some IMO not really impressive Viva Pinata minigames and IMO with the most impressive title shown Assassin's Creed which is a multi-platform title shared with the PS3. Nintendo showed Wii Fit which may not appeal to everyone, but I liked it, it seems like a modern version of the Amiga joyboard from 1982.
Killzone is awesome!