I'm currently working out final details for my grail with Alan Davis, a small 6" (OAL) fixed blade drop point of my own design and with ergonomics fitted to my hand, with desert ironwood scales and Damascus steel. The design and materials are not particularly exotic, original, or radical, but neither am I.
What makes it a grail in my mind is that is mine. I conceived of it, drew it, made models of the handle and blade, discussed the details with Alan, and am getting it made. No other knife I buy is ever likely to be mine in quite the same way. The fact it will likely be the single most expensive knife I ever purchase is irrelevant, as there are plenty of production knives that are more expensive. Those aren't mine.