I know what he is wearing is very simple, not remotely directional or even bespoke-ish but I would love to look this cool in a suit someday. I would love to tell you "well he looks great specifically because of...blah, blah" but there really isn't one thing that stands out - it all is just so well played - the "unstyled" stylish haircut, the slightly rumpled wool suit, the casual dark navy knit tie, the sporty watch, and I would be willing to bet that he is wearing a Brooks Brothers buttondown (unbuttoned-down notice!) shirt.
As I keep looking at this image the only thing that I can keep coming back to is the fact that his clothes just fit him so perfectly. He could wear exactly all the same items but if they didn't fit on him as well as they do then this would not be such an inspiring photo.
You can do it guys, you can get this look with a $500 suit -just make sure to spend the extra on having it altered.