The Xbox 360. It was really something special and innovative. Dual CPUs was not that common, and there they were coming out with a tri core processor? On a Game Machine? Crazy.
Plus, I thought Kinect was innovated (we now have Alexia and OK Google, and all those filters (ah la KinectTV Party) etc.)
I think they should have held back the Xbox One for a year and had it ready when it came out.