Actually I think it's the most important thing for everybody, and it has nothing to do with preference or choice, I'm just saying it's "important". To some extent, how you view death or what you believe about death or afterlife affect your attitude towards life (including career and family) and the world when you are still alive, which in turn determin your whole life and fate. An example would be religion's effect on people.

Or, look at it in a simpler way, it's the division of two worlds, the door to something which is still a mystery to human beings. When we are still alive, we have choices and controls, but once we step over, we lose everything. In Japan, there is the story that one was asked to write apothegms on a piece of paper miles long, he didn't spend days on it, because he just wrote a big "death".

"love" is another answer, but if there's only one, I would say "death". You are the first one ever asked me this question. I'd like to know what you think about it:-)