For me many factors, where its made, by who, reason behind(be it EDC, military etc etc)reliability, build, warranty, LED and driver choices. So i like in ways a story, be it Henry with HDS with caving and Hogo's part. Developments over the years(decades) no matter how small and maybe not even noticeable......yet improvements. PK with the older surefires, his ideas and designs today put many new lights in the dark. Malkoff and oveready for their ideas and designs as well as the others mentioned. I am sure the WANT comes into it as well haha.
So USA made appeals to me, custom made in some cases. Admittedly some price points i cant afford to easy or at the drop of a hat, not because i dont think it may be worth it, but more on the not having the spare funds.
Be it good or bad, i am at the point of having not too many, but far too many. So i am far more fussy in what i buy or consider than say 3 or 4 years back. Pretty much as i have it mainly covered several times over.
A hanko and okluma dark ti at some point in the future maybe an option. Of course i could sell a few to self fund, but damn and blast i get attached to them all