It would have been easiest for me to vote for "bang per buck", which is all any of us really do. All the non-price attributes roll up into a subjective measure of "bang".
Not to take the easy way out, I voted for the most relevant parts of "bang" for me which are steel and shape - these together (with modifiers such as heat treat, brand = quality, etc. as mentioned by several dogs) really dictate function. Since I buy knives to use (i.e. for functionality), divide functionality by price and you have my criteria.
Good poll!
