For me, it's leadership. I got a very good offer with a well-known company, but my level is not what I aim after MBA. I decided to take another job with higher level, which I have impact on the company.
I think I would agree with aaudetat.
Though depending on your financial situation, money can be important, I usually find that great companies with good leadership pay more than others, so in my experience, good environment always always coincided with good pay.
Are you in a similar situation or it is a rather hypothetical question?