I'm going to go against the grain here and say Financial Success* is more important than Personal Happiness, at this point in my life. What can I say? This question caught me at time when I'm willing to sacrifice personal happiness to build wealth. Ask me again in 30 years and the answer might be different =)
It's a matter of 先苦後甜; "bitter first; sweet later".
In the grand scheme of things, choosing one over the other is not really the point. It's more important to not let either of them take a disproportional precedence over the other. Ideally, over the long term you'd want both to increase in tandem, but there will be times when one of them needs to be sacrificed for the sake of the other.
Financial success without personal happiness is miserable. People I trust tell me it's true, but I've never known this kind of misery. I'd always thought that if money weren't a concern, I would damned well find it in myself to be happy.
Personal happiness without some degree of financial success/independence is not possible for me. It may work for others, but not me. I'd go stark raving bananas before long if I weren't financially independent or at least on my way towards it. In that way, my happiness is tied to my financial success.
* I define "financial success" as financial independence which is to be self-sufficient in being able to meet basic needs: clothing, shelter, food, health, even though those needs can be met without the exchange of funds. For me, it has very little to do with the actual numbers in anyone's bank account or cashflow. However someone else decides is best for them to meet their basic needs, and beyond, is not really for me to judge.