I am one of those people who believes that "good nature" constitutes beauty, at least to some extent. I don't know that I would be able to actually choose one of these three qualities as the basis of a permanent relationship, but that is my initial response. I'd order good nature first.

If I had to choose one of the choices it would be 'good nature'. I assume you mean someone who is engaging and fun to be around. If I could, I would add trust to the mix. A long term relationship must be built on a foundation of trust. If this component of trust is absent I think the relationship is doomed.

Good nature is the best quality.  Beauty fades.  Something that is beautiful on the outside and not the inside will start to look ugly pretty quickly as well.  Money isn't of much value if you have to share it with a jerk.  Think about it.  You can always make more money, but you can't make someone nicer.  Money is also an uncertainty.  Just like beauty, it can fade.  The economy can change or money can lose it's value in other ways as well.  A good natured partner will be beautiful to you.  It won't matter how much or how little money you have when you have a good partner to share it with.

Of your three choices I would have to say good nature.  As I sought out someone to spend my life with, I was looking for someone who shared my core values and beliefs.

It has to be "good nature" if you really want someone you can life with your whole life.  That's going to be way more important than the others.  After that comes money because beauty fades and beauty can't really reduce the stresses of life the way that having enough money can.

If it is really going to be a "life" partner, then I'd have to choose a good nature. You want someone that is going to be compatible with you and that you enjoy spending time with. Otherwise the rest of it isn't going to matter.

I've found that someone that you may not initially find you may not initially find "beautiful" often becomes that way once you get to know them. The nicer somebody is the better they look. I don't know if anybody else has noticed that, but I have.