In Pot on the Fire John Thorne writes: "Cooks, at least serious cooks, can be roughly divided into two major groups: pot cooks and knife cooks." He goes on to say: "Of course, each sort uses both implements; it is a matter of which serves as the lodestone of their kitchen - the piece of cookware that, in case of fire, they would run to rescue first."
My favorite knife is a no-name 7-inch chef's knife that my parents brought me from Spain some 15 years ago. It fits me perfectly and I reach for it 70 percent of the time. But then a friend gave me a Wusthoff santoku and were my kitchen on fire I might be tempted to run back in and save it too. ( Larger image.)
A standard chef's knife (the top blade in the photo) has a rounded blade designed to be used in a rocking motion when slicing and dicing. A santoku blade has a straight edge. The straight edge struck me as worthless so when this Japanese blade style became popular back in the 90s I figured it was a fad and ignored it until I was given one. (Actually, it cost me a nickel because according to lore a friend should never simply give a friend a knife lest it cut their friendship.)
I tried the knife on some typical chores and wasn't overly impressed, but when I used it to dice an onion I discovered the great advantage of a straight edge - it was easier to make the horizontal cuts in the onion half and then easier still to cut down straight to make the dice.
Over time I learned that for chopping-type work (tasks involving a mostly up and down motion) on vegetables I've developed a real fondness for the santoku. It's perfect for dicing carrots, onions, and celery for mirepoix or simply cutting vegetables into chunks. I use it to dice cooked chicken for chicken salad and to cut thin slices of potato for Potatoes Anna.
In the event of a fire, I would still rescue my Spanish chef's knife first, but if I could save a second knife it would be the santoku. If you have a little extra cash for an extra knife, try one. I can almost guarantee you'll like it.