From the point of view of future earnings and job prospects, ACA (i.e. ICAI) would probably be the 'best', but that assumes you can stick 3-3.5 years of auditing! Also that you can secure a training contract with a 'Big 4' firm that will pay you a decent salary while training and allow fairly generous study time. BTW, I am an ACA, but would not look down my nose at any if the other bodies, as some on AAM have done!