I do believe that quality, personal as it can be, has its own rules and obeys to some "general" rules that go beyond personal preference. It's not an absolute feature, but it comes quite close to it, especially in some cathegories.
Example. As much as I can try, I think it's useless to convince anyone that my Winchester jack is "better" than Ken Erickson's swell center jack. It's not. Period.
We're talking about knives...but the same thing could be said about cars, bikes, beautiful women (and men of course), or anything else.
I admit that I have more tolerance for quality as a universal if we're talking about superlative style, design and execution. I think most people will recognize something as being representative of the ultimate expression of that kind of thing, at least at an intellectual level. But, opinions vary so widely on style and design philosophy, it's still hard to get agreement. Leroy Remer is generally recognized as the, or one of they top Buck customizers, having worked in Buck's custom shop for many years. I can look at his "fantasy" knives, recognize the craftsmanship as being "the best" but the knife just leave me cold as a dead fish.
Somewhat more down to earth, David and Brian Yellowhorse are widely recognized for the artistry of their marriage of Buck customization with traditional Native American art. Again, I can intellectually accept them as "the best" in some sense, even if it's not my preferred style.
Opinions vary on the issue of design. I (mistakenly) hijacked Jack Black's recent thread on Victorinox knives. The thrust of the thread was that Victorinox is the best (or nearly the best) as consistent production and QC, a point that nobody in their right mind will dispute. But, IMO, their designs are... well... awful. The blades, while superbly well made with nearly perfect QC are soft and really, who can actually carry and use this monstrosity?
Favorite is a better word for me than best. Back in the day when I used to hang out on usenet's rec.backcountry we would often see threads like "What is the best backpack?". My response was, "Best for what?" This is where favorites come in, imo. I have different favorite knives for different things.
Christian's great question reveals that something can be "the best" but not the best for some task.
Here's my favorite combo
for everyday carry. Nobody is going to argue that either of these knives is the best in any way shape or form in terms of their manufacture or quality. They are well designed, to be sure. They work well and are perfectly suited to my uses. But not "the best" in that universally recognizable way.
edc-pair by
Pinnah, on Flickr