Happiness without a single doubt. It is the core of obtaining the other two.
If you are unhappy you can attain wealth still, but it is likely that your health will suffer.
If you are unhappy you can maintain your health (maybe) but you will likely end up working for the man the rest of your life just to maintain your medical bills and prescription costs.
But, if you are truly happy then you'll find yourself with much more energy to pursue life, suffer less physical and mental illness and be able to focus yourself on attaining success and achieving wealth.
just my
