None. They are tools. I don't have a hammer, wrench, set of punches, multimeter, or calipers that I like more than the others.
I have had least-prized guns before, that were quickly sold off. For me, a gun is either "prized" or it is worthless. I'm not a collector. Every gun I own, even family heirlooms built before my parents were born, are fired and used (usually, on every range trip, too).