California is often criticized for its budget crisis. However, looking more into the state's finances, it appears that California only receives 78 cents from the Federal Government per dollar paid in taxes, thus it is reasonable to believe that California could be better off alone.
California alone is, with a GDP of 1.8 trillion dollars, the 8th largest economy in the world. The following infographic of California, created by Visual Economics, gives an interesting visualization of how California sizes up to the rest of the world.