PS3!
I read on
www.gamevolume.com that the PS3 game-developeres can only produce games there are up to 10% of what the ps3 can do. So in 6 months or more you will se games there will kick Wii and X-360 to the curve.
Also that the PS3 use the Blueray tech. That will also be a major factor - because they developers can make some really big and resource-demanding games that never can run on the other 2 consols by disks