1- Europe (remember Italy, French, UK and Germany are 4 world's power) 2- USA 3- China.

2006 GDP Figures from the CIA World Fact book, in Trillions of dollars, purchasing power parity:

European Union: 13.080

United State: 13.060

China: 10.210

Prior to 2005, and probably back to 1942, the United State surpassed the EU.