I agree that the best job is one where you enjoy being there, enjoy the type of activity and the people you interact with. Aptitude for the activity is important, but saying it should be 'your passion' is often difficulty. Having work that you enjoy that allows you to pursue your passion is, today, more often a reasonable goal. I was in a profession that I was encouraged to pursue by my parents, having two older siblings who were successful in it. Was I truly happy in it? No, but I made the best of it and it provided very well for my family. If I had my choice and had been encouraged when I was younger, I would have pursed my dream and gone into medicine. I also would have had a very difficult time transitioning in the culture of my profession. As a result, I didn't. I waited and waited and waited. Until now........
For me, at the moment, the 'Best Job' is the one I am in - retirement! I am coming up to my first anniversary of coming out to my wife, and my start on this wonderful path.