What's best?

I wrote my dissertation on choosing.  It could be called "deciding on a choice".  It is easy to find choosing discussion that refers to "optimal choice".   That "optimal" is usually meant to mean "best".  But since I have taught that bugbear subject, grading, too, I realize that there are nearly always many different "bests" depending on the chooser and the situation.  In addition to different approaches and definitions of what is best, there is often a price involved.  One class of smarties gave me a t-shirt with "How much?" on it because I asked them so often if their 'best" was much better or just a tiny bit better than the nearest competitor.